[llvm] [Github] Make issue write workflow only run after success/failure (PR #97341)

[Tom Stellard via llvm-commits]

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

LGTM. Thanks.

Once https://github.com/llvm/llvm-project/pull/94011 is merged then I think it might make sense to do a follow up to skip this action if the artifact is missing.  That seems a little more robust.

https://github.com/llvm/llvm-project/pull/97341