Build: Bump org.openapitools:openapi-generator-gradle-plugin (#12435)

Bumps [org.openapitools:openapi-generator-gradle-plugin](https://github.com/OpenAPITools/openapi-generator) from 7.11.0 to 7.12.0.
- [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@v7.11.0...v7.12.0)

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

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

Author: dependabot[bot]

build.gradle

@@ -36,7 +36,7 @@ buildscript {
     classpath 'org.revapi:gradle-revapi:1.8.0'
     classpath 'com.gorylenko.gradle-git-properties:gradle-git-properties:2.4.2'
     classpath 'com.palantir.gradle.gitversion:gradle-git-version:3.1.0'
-    classpath 'org.openapitools:openapi-generator-gradle-plugin:7.11.0'
+    classpath 'org.openapitools:openapi-generator-gradle-plugin:7.12.0'
   }
 }