Bump apicurio.registry.version from 2.5.11.Final to 2.6.4.Final

Bumps `apicurio.registry.version` from 2.5.11.Final to 2.6.4.Final.

Updates `io.apicurio:apicurio-registry-schema-resolver` from 2.5.11.Final to 2.6.4.Final
- [Release notes](https://github.com/apicurio/apicurio-registry/releases)
- [Commits](Apicurio/apicurio-registry@2.5.11.Final...2.6.4.Final)

Updates `io.apicurio:apicurio-registry-protobuf-schema-utilities` from 2.5.11.Final to 2.6.4.Final

Updates `io.apicurio:apicurio-registry-schema-util-protobuf` from 2.5.11.Final to 2.6.4.Final

---
updated-dependencies:
- dependency-name: io.apicurio:apicurio-registry-schema-resolver
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.apicurio:apicurio-registry-protobuf-schema-utilities
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.apicurio:apicurio-registry-schema-util-protobuf
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -76,7 +76,7 @@
         <version.maven-javadoc-plugin>3.5.0</version.maven-javadoc-plugin>
         <version.maven-source-plugin>3.2.1</version.maven-source-plugin>
         <version.maven-compiler-plugin>3.11.0</version.maven-compiler-plugin>
-        <apicurio.registry.version>2.5.11.Final</apicurio.registry.version>
+        <apicurio.registry.version>2.6.4.Final</apicurio.registry.version>
         <json-schema-validator.version>1.4.0</json-schema-validator.version>
         <org.json.version>20240303</org.json.version>