Complete Joda-Time to java.time migration (#3039)

This completes the exhaustive refactoring of foundational temporal types from Joda-Time to the native java.time API across the entire codebase.

- Replaced org.joda.time.DateTime, Instant, LocalDate, and Duration with java.time equivalents.
- Audited and updated Clock implementations (FakeClock, SystemClock). Added nowMillis(), nowDate(), and nowDateTime() to eliminate repetitive conversions and maintain parallel naming.
- Replaced ZonedDateTime with OffsetDateTime globally per go/avoid-zdt. OffsetDateTime is a better fit as we use a hardcoded ZoneOffset.UTC throughout the system, making geographical time zone rules (like daylight saving time) irrelevant and preventing serialization ambiguities. Added a presubmit check.
- Completely removed all transitional bridge methods from DateTimeUtils and deleted obsolete converters (e.g., DateTimeConverter).
- Updated testing infrastructure, Apache Beam pipelines, custom JCommander parameters, and networking modules to solely rely on java.time primitives.
- Retained the lone necessary org.joda.time.Instant usage in SafeBrowsingTransforms required by the Apache Beam API.
- Cleared Gradle lockfiles and removed the joda-time dependency entirely from the build configuration.

networking/gradle.lockfile

@@ -109,7 +109,6 @@ jakarta.mail:jakarta.mail-api:2.2.0-M1=deploy_jar,runtimeClasspath,testRuntimeCl
 jakarta.xml.bind:jakarta.xml.bind-api:4.1.0-M1=deploy_jar,runtimeClasspath,testRuntimeClasspath
 javax.annotation:javax.annotation-api:1.3.2=deploy_jar,runtimeClasspath,testRuntimeClasspath
 javax.inject:javax.inject:1=annotationProcessor,compileClasspath,deploy_jar,runtimeClasspath,testAnnotationProcessor,testCompileClasspath,testRuntimeClasspath
-joda-time:joda-time:2.14.2=deploy_jar,runtimeClasspath,testCompileClasspath,testRuntimeClasspath
 junit:junit:4.13.2=testCompileClasspath,testRuntimeClasspath
 net.java.dev.jna:jna:5.13.0=testCompileClasspath,testRuntimeClasspath
 net.ltgt.gradle.incap:incap:0.2=annotationProcessor,testAnnotationProcessor

networking/src/test/java/google/registry/networking/handler/SslClientInitializerTest.java

@@ -19,7 +19,6 @@ import static google.registry.networking.handler.SslInitializerTestUtils.getKeyP
 import static google.registry.networking.handler.SslInitializerTestUtils.setUpSslChannel;
 import static google.registry.networking.handler.SslInitializerTestUtils.signKeyPair;
 import static google.registry.networking.handler.SslInitializerTestUtils.verifySslException;
-import static org.joda.time.DateTimeZone.UTC;
 
 import com.google.common.collect.ImmutableList;
 import google.registry.testing.FakeClock;
@@ -45,10 +44,11 @@ import java.security.cert.CertificateException;
 import java.security.cert.CertificateExpiredException;
 import java.security.cert.CertificateNotYetValidException;
 import java.security.cert.X509Certificate;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.stream.Stream;
 import javax.net.ssl.SSLException;
 import javax.net.ssl.SSLSession;
-import org.joda.time.DateTime;
 import org.junit.jupiter.api.extension.RegisterExtension;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
@@ -243,7 +243,11 @@ class SslClientInitializerTest {
     SelfSignedCaCertificate ssc = SelfSignedCaCertificate.create(new FakeClock());
     X509Certificate cert =
         signKeyPair(
-            ssc, keyPair, SSL_HOST, DateTime.now(UTC).minusDays(2), DateTime.now(UTC).minusDays(1));
+            ssc,
+            keyPair,
+            SSL_HOST,
+            Instant.now().minus(2, ChronoUnit.DAYS),
+            Instant.now().minus(1, ChronoUnit.DAYS));
 
     // Set up the server to use the signed cert and private key to perform handshake;
     PrivateKey privateKey = keyPair.getPrivate();
@@ -280,7 +284,11 @@ class SslClientInitializerTest {
     SelfSignedCaCertificate ssc = SelfSignedCaCertificate.create(new FakeClock());
     X509Certificate cert =
         signKeyPair(
-            ssc, keyPair, SSL_HOST, DateTime.now(UTC).plusDays(1), DateTime.now(UTC).plusDays(2));
+            ssc,
+            keyPair,
+            SSL_HOST,
+            Instant.now().plus(1, ChronoUnit.DAYS),
+            Instant.now().plus(2, ChronoUnit.DAYS));
 
     // Set up the server to use the signed cert and private key to perform handshake;
     PrivateKey privateKey = keyPair.getPrivate();

networking/src/test/java/google/registry/networking/handler/SslInitializerTestUtils.java

@@ -15,7 +15,6 @@
 package google.registry.networking.handler;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.joda.time.DateTimeZone.UTC;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import com.google.common.base.Throwables;
@@ -28,6 +27,9 @@ import java.security.KeyPair;
 import java.security.KeyPairGenerator;
 import java.security.SecureRandom;
 import java.security.cert.X509Certificate;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.Date;
 import java.util.concurrent.ExecutionException;
 import javax.net.ssl.SSLSession;
 import org.bouncycastle.asn1.x500.X500Name;
@@ -38,7 +40,6 @@ import org.bouncycastle.cert.jcajce.JcaX509v3CertificateBuilder;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.operator.ContentSigner;
 import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
-import org.joda.time.DateTime;
 
 /**
  * Utility class that provides methods used by {@link SslClientInitializerTest} and {@link
@@ -72,7 +73,7 @@ public final class SslInitializerTestUtils {
    * @return signed public key (of the key pair) certificate
    */
   public static X509Certificate signKeyPair(
-      SelfSignedCaCertificate ssc, KeyPair keyPair, String hostname, DateTime from, DateTime to)
+      SelfSignedCaCertificate ssc, KeyPair keyPair, String hostname, Instant from, Instant to)
       throws Exception {
     X500Name subjectDnName = new X500Name("CN=" + hostname);
     BigInteger serialNumber = BigInteger.valueOf(System.currentTimeMillis());
@@ -82,8 +83,8 @@ public final class SslInitializerTestUtils {
         new JcaX509v3CertificateBuilder(
             issuerDnName,
             serialNumber,
-            from.toDate(),
-            to.toDate(),
+            Date.from(from),
+            Date.from(to),
             subjectDnName,
             keyPair.getPublic());
 
@@ -102,7 +103,11 @@ public final class SslInitializerTestUtils {
   public static X509Certificate signKeyPair(
       SelfSignedCaCertificate ssc, KeyPair keyPair, String hostname) throws Exception {
     return signKeyPair(
-        ssc, keyPair, hostname, DateTime.now(UTC).minusDays(1), DateTime.now(UTC).plusDays(1));
+        ssc,
+        keyPair,
+        hostname,
+        Instant.now().minus(1, ChronoUnit.DAYS),
+        Instant.now().plus(1, ChronoUnit.DAYS));
   }
 
   /**