Add CI to improve experience for community (#8779)

* Add CI to improve experience for community

* Fix close-if-fork-develop if-condition

* Extract into reusable workflow

.github/workflows/pull_request.yaml

@@ -4,23 +4,7 @@ on:
     types: [ opened, edited, labeled, unlabeled, synchronize ]
 concurrency: ${{ github.workflow }}-${{ github.event.pull_request.head.ref }}
 jobs:
-  changelog:
-    name: Preview Changelog
-    if: github.event.action != 'synchronize'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: matrix-org/allchange@main
+  action:
+    uses: matrix-org/matrix-js-sdk/.github/workflows/pull_request.yaml@develop
     with:
-          ghToken: ${{ secrets.GITHUB_TOKEN }}
-
-  enforce-label:
-    name: Enforce Labels
-    runs-on: ubuntu-latest
-    permissions:
-      pull-requests: read
-    steps:
-      - uses: yogevbd/enforce-label-action@2.1.0
-        with:
-          REQUIRED_LABELS_ANY: "T-Defect,T-Enhancement,T-Task"
-          BANNED_LABELS: "X-Blocked"
-          BANNED_LABELS_DESCRIPTION: "Preventing merge whilst PR is marked blocked!"
+      labels: "T-Defect,T-Enhancement,T-Task"