Update check changelog worfklow (#133)

Updates the check changelog check to match the newer iteration in other repos, eg:
https://github.com/heroku/heroku-buildpack-python/blob/main/.github/workflows/check_changelog.yml

Signed-off-by: Ed Morley <[email protected]>

Author: edmorley

.github/workflows/check_changelog.yml

@@ -1,12 +1,20 @@
 name: Check Changelog
 
-on: [pull_request]
+on:
+  pull_request:
+    types: [opened, reopened, labeled, unlabeled, synchronize]
+
+permissions:
+  contents: read
 
 jobs:
- build:
-   runs-on: ubuntu-latest
-   steps:
-   - uses: actions/checkout@v1
-   - name: Check that CHANGELOG is touched
-     run: |
-       cat $GITHUB_EVENT_PATH | jq .pull_request.title |  grep -i '\[\(\(changelog skip\)\|\(ci skip\)\)\]' ||  git diff remotes/origin/${{ github.base_ref }} --name-only | grep changelog.md
+  check-changelog:
+    runs-on: ubuntu-latest
+    if: (!contains(github.event.pull_request.labels.*.name, 'skip changelog'))
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Check that CHANGELOG is touched
+        run: |
+          git fetch origin ${{ github.base_ref }} --depth 1 && \
+          git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md