[llvm] [Workflows] Enable commit access requests via GitHub issues (PR #100458)

[Tom Stellard via llvm-commits]

================
@@ -27,3 +27,6 @@
 
 'bolt':
   - '/\bbolt(?!\-)\b/i'
+
+'infrastructure:commit-access-request':
----------------
tstellar wrote:

We already have the `infrastructure` label and I was trying to follow our convention of sub-labels.  I think if we do s/infrastructure/infra/ here, then we should do it for all labels.

https://github.com/llvm/llvm-project/pull/100458