Upgrade to Jakarta EE 10 Servlet (#2362)

Upgrade to using Jakarta EE 10 from Java EE 8 by mostly following the upgrade instructions. Only the servlet package is upgrade. Other Jakarta EE components (like the persistence package that Hibernate depends on) need to be upgraded separately.

TESTED=deployed and successfully communicated with the pubapi endpoint for web WHOIS.

Note that this currently requires packaing the App Engine runtime per instructions here due to GoogleCloudPlatform/appengine-java-standard#98. This PR will only be merged until the fix is deployed to production (https://rapid.corp.google.com/#/release/serverless_runtimes_run_java/java21_20240310_21_0).

dependencies.gradle

@@ -186,10 +186,10 @@ ext {
       'io.github.classgraph:classgraph:[4.8.102,)',
       'io.github.java-diff-utils:java-diff-utils:[4.9,)',
       'io.netty:netty-tcnative-boringssl-static:[2.0.36.Final,)',
+      'jakarta.servlet:jakarta.servlet-api:[6.0,)',
       // Upgrade to jakarta when we remove App Engine dependency
       'javax.mail:mail:[1.4,)',
       'javax.persistence:javax.persistence-api:[2.2,)',
-      'javax.servlet:servlet-api:[2.5,)',
       'javax.xml.bind:jaxb-api:[2.3.0,)',
       'joda-time:joda-time:[2.9.2,)',
       'junit:junit:[4.13,)',
@@ -216,8 +216,6 @@ ext {
       'org.bouncycastle:bcprov-jdk18on:[1.67,)',
       'org.checkerframework:checker-compat-qual:[2.5.5,)',
       'org.checkerframework:checker-qual:[3.9.1,)',
-      'org.eclipse.jetty:jetty-server:[9.4.49.v20220914,)',
-      'org.eclipse.jetty:jetty-servlet:[9.4.49.v20220914,)',
       'org.flywaydb:flyway-core:[10.0.0,)',
       'org.flywaydb:flyway-database-postgresql:[10.0.0,)',
       'org.hamcrest:hamcrest-core:[2.2,)',
@@ -235,7 +233,9 @@ ext {
       'org.junit.platform:junit-platform-suite-api:[1.6.2,)',
       'org.mockito:mockito-core:[3.7.7,)',
       'org.mockito:mockito-junit-jupiter:[3.7.7,)',
-      'org.mortbay.jetty:jetty:[6.1.26,)',
+      'org.eclipse.jetty:jetty-server:[12.0.0,)',
+      'org.eclipse.jetty.ee10:jetty-ee10-servlet:[12.0.0,)',
+      'org.eclipse.jetty.ee10:jetty-ee10-webapp:[12.0.0,)',
       'org.ogce:xpp3:[1.1.6,)',
       'org.postgresql:postgresql:[42.2.18,)',
       'org.slf4j:slf4j-jdk14:[1.7.28,)',