Bump org.openapitools:openapi-generator from 7.7.0 to 7.8.0

Bumps [org.openapitools:openapi-generator](https://github.com/openapitools/openapi-generator) from 7.7.0 to 7.8.0.
- [Release notes](https://github.com/openapitools/openapi-generator/releases)
- [Changelog](https://github.com/OpenAPITools/openapi-generator/blob/master/docs/3.0.0-release-note.md)
- [Commits](OpenAPITools/openapi-generator@v7.7.0...v7.8.0)

---
updated-dependencies:
- dependency-name: org.openapitools:openapi-generator
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

contract/build.gradle

@@ -88,5 +88,5 @@ dependencies {
     implementation "com.google.protobuf:protobuf-java:${protoVersion}"
     runtimeOnly "com.google.protobuf:protobuf-java-util:${protoVersion}"
     implementation group: 'org.apache.avro', name: 'avro', version: '1.12.0'
-    implementation 'org.openapitools:openapi-generator:7.7.0'
+    implementation 'org.openapitools:openapi-generator:7.8.0'
 }