[llvm] workflows/release-tasks: Setup FileCheck and not for release-lit (PR #66799)

[Tobias Hieta via llvm-commits]

tru wrote:

Thanks for your work on this! I think we should merge this, but probably also spin it out to its own action to run on the release branch PRs since this current workflow only runs when we make a new release. And at that point it's almost "too late". We ideally would use this feedback earlier in the release to fix issues.

https://github.com/llvm/llvm-project/pull/66799