Upgrade to Node 20 on CI, enable actions cancellation (#24524)

- Upgrade node, the
[snap](7abe958f5b/snap/snapcraft.yaml (L47))
is excluded from this because [there is no Node 20 snap
yet](https://snapcraft.io/node).
- Add actions build cancellation based on
[this](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#example-using-a-fallback-value).

---------

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

.github/workflows/pull-compliance_docs.yml

@@ -6,6 +6,10 @@ on:
       - "docs/**"
       - "*.md"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   compliance-docs:
     runs-on: ubuntu-latest
@@ -13,9 +17,9 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
       - name: setup node
-        uses: actions/setup-node@v2
+        uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 20
       - name: install dependencies
         run: make deps-frontend
       - name: lint markdown