Bump confluentVersion from 7.6.1 to 7.7.1 (#601)

Bumps `confluentVersion` from 7.6.1 to 7.7.1.

Updates `io.confluent:kafka-schema-registry-client` from 7.6.1 to 7.7.1
- [Commits](confluentinc/schema-registry@v7.6.1...v7.7.1)

Updates `io.confluent:kafka-json-schema-provider` from 7.6.1 to 7.7.1
- [Commits](confluentinc/schema-registry@v7.6.1...v7.7.1)

---
updated-dependencies:
- dependency-name: io.confluent:kafka-schema-registry-client
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.confluent:kafka-json-schema-provider
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

build.gradle.kts

@@ -77,7 +77,7 @@ subprojects {
         set("mockitoVersion", "5.13.0")          // https://mvnrepository.com/artifact/org.mockito/mockito-junit-jupiter
         // Update kafka_version in `.github/workflows/build.yml` when updating this version
         set("kafkaVersion", "3.7.0")            // https://mvnrepository.com/artifact/org.apache.kafka
-        set("confluentVersion", "7.6.1")        // https://packages.confluent.io/maven/io/confluent/kafka-schema-registry-client
+        set("confluentVersion", "7.7.1")        // https://packages.confluent.io/maven/io/confluent/kafka-schema-registry-client
         set("testContainersVersion", "1.19.8")  // https://mvnrepository.com/artifact/org.testcontainers/testcontainers
     }