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.yml

@@ -2,6 +2,10 @@ name: "Pull: Compliance Tests"
 
 on: [pull_request]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   lint_basic:
     runs-on: ubuntu-latest
@@ -79,7 +83,7 @@ jobs:
       - name: setup node
         uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 20
       - name: deps-frontend
         run: make deps-frontend
       - name: lint frontend
@@ -100,7 +104,7 @@ jobs:
       - name: setup node
         uses: actions/setup-node@v3
         with:
-          node-version: 18
+          node-version: 20
       - name: deps-backend
         run: make deps-backend deps-tools
       - name: deps-frontend