[llvm] [docs] Update Qualification WG working processes (PR #224904)

[via llvm-commits]

uwendi wrote:

Two Working Group members have reviewed and approved the change. The documentation build and other relevant checks passed. The remaining libc++ Buildkite failure occurred in the pipeline-generation step before any build or test jobs ran and appears unrelated to this documentation-only change. I will therefore proceed with the merge.

https://github.com/llvm/llvm-project/pull/224904