[llvm] workflows/release-documentation: Remove permission check from validation job (PR #211718)

[Aiden Grossman via llvm-commits]

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

LGTM.

Permission check is here (https://github.com/llvm/llvm-project/blob/4f8de7694a0aab7a55c21970855dd8659f3700c6/.github/workflows/upload-release-artifact/action.yml#L104) in case anyone else is looking.

https://github.com/llvm/llvm-project/pull/211718