[llvm] workflows/release-sources: Make sure to checkout all the composite actions (PR #212544)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

I'm guessing the time to checkout .github vs specific actions is extremely low, but might be good to validate somewhere.

https://github.com/llvm/llvm-project/pull/212544