Remove compareTo() from DelegationSignerData

The only reason why it existed was so that we could get tests to print information in a consistent order and there are other ways of doing that. By removing compareTo we can use the properties of the extended ImmutableObject properly and properly implement the RFC https://tools.ietf.org/html/rfc5910#page-18

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=240170488

java/google/registry/model/domain/secdns/DelegationSignerData.java

@@ -30,8 +30,7 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
  */
 @Embed
 @XmlType(name = "dsData")
-public class DelegationSignerData
-    extends ImmutableObject implements Comparable<DelegationSignerData> {
+public class DelegationSignerData extends ImmutableObject {
 
   /** The identifier for this particular key in the domain. */
   int keyTag;
@@ -85,11 +84,6 @@ public class DelegationSignerData
     return instance;
   }
 
-  @Override
-  public int compareTo(DelegationSignerData other) {
-    return Integer.compare(getKeyTag(), other.getKeyTag());
-  }
-
   /**
    * Returns the presentation format of this DS record.
    *