GH Actions: validate Renovate config

Author: MetRonnie

.github/workflows/renovate_validate.yml

@@ -0,0 +1,30 @@
+name: Validate Renovate config
+
+on:
+  pull_request:
+    paths:
+      - renovate.json
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  FORCE_COLOR: 2
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 'lts/*'
+
+      - name: Validate config
+        run: npx --yes --package renovate -- renovate-config-validator