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

[Vlad Serebrennikov via llvm-commits]

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

I'm not insisting on `infra` in particular (even though I prefer it, and renaming labels is easy), but I do have general concerns over the length. Almost all the labels we have at the moment are at least as half as short of what is proposed here, and `infrastructure` eats a lot of space as a prefix.

I can rename existing `infrastructure` labels to `infra` if that's the only blocker.

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