Switch to release of jbang-gradle-plugin

[koppor]

Update to the release where jbangdev/jbang-gradle-plugin#21 is included.

At #14725, we use "com.github.koppor:jbang-gradle-plugin:jitpack-SNAPSHOT"), and we should switch back to the original tool.

[github-actions]

We think that this issue was fixed. Please head to https://builds.jabref.org/main to download a development build and try it out.

For any feedback, add a comment to the pull request at #14776.