what's the right way to setup Gradle on Github CI? This? Also, does this still make sense?

# Enable gradle cache: <https://github.com/actions/cache/blob/master/examples.md#java---gradle>
      - uses: actions/cache@v4

right way

That's a matter of definition. You can use the official actions you linked to. You can use https://github.com/burrunan/gradle-cache-action You can just call the Gradle wrapper. Each has its pros and cons.

Each has its pros and cons.

That's exactly what I'm eager to know, would you mind elaborating a little about that? Or if you have some interesting link?

Unfortunately not. Two examples. The action from burrunan for example provides a remote build cache to store single build cache entries in the GitHub cache instead of just the whole bunch. The official action on the other hand has some support for configuration cache if setup properly.

this might be interesting for others, in case

Yeah, unfortunately it does not compare to burrunan's action and neither does the docs of that one. Maybe @Vladimir Sitnikov can share some insights.