Update actions

[sormuras]

Update actions used by this action to their latest version. Including:

• actions/checkout
• actions/setup-java

[joel-costigliola]

Hey @sormuras,
The AssertJ team updated our builds to pin actions to SHA instead of versions, one of our build broke complaining that we could not use actions/setup-java@v4.

I suspect it is due to this line https://github.com/oracle-actions/setup-java/blob/main/action.yml#L78.

Since this issue is about updating actions, would it make sense to also pin actions to SHA as recommended by Github.

Thanks for this useful project !