build: run ASF allowlist check on every PR so the required check reports (#8887)

The workflow had a paths filter (.github/**) on the pull_request trigger, so
it only ran when a PR touched .github/**. Since asf-allowlist-check is a
required status check in .asf.yaml, every other PR stayed in the 'Expected —
waiting for status' state and could never be merged.

Drop the paths filter on pull_request (mirroring apache/opennlp) so the check
runs and reports a status on all PRs. The push trigger keeps its paths filter.

Author: rzo1

.github/workflows/asf-allowlist-check.yml

@@ -17,9 +17,10 @@ name: ASF Allowlist Check
 
 on:
   workflow_dispatch:
+  # No paths filter on purpose: as a required status check (see .asf.yaml) this
+  # job must report a status on every PR, otherwise PRs that don't touch
+  # .github/** would stay "Expected — waiting for status" and be blocked forever.
   pull_request:
-    paths:
-      - ".github/**"
   push:
     branches: [ "master", "2.x" ]
     paths: