Add linting job

Signed-off-by: Marco Franssen <[email protected]>

.github/workflows/test.yml

@@ -3,9 +3,49 @@ name: Test Charts
 on:
   pull_request:
     paths:
+      - ".github/workflows/test.yml"
       - "charts/**"
 
 jobs:
+  build-matrix:
+    name: Find charts
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # pin@v3
+        with:
+          fetch-depth: 0
+
+      - name: Find charts
+        id: build-matrix
+        run: |
+          charts=$(find charts -type f -name 'Chart.yaml' | sed -r 's|/[^/]+$||' | sort | uniq | jq -c --slurp --raw-input 'split("\n") | map(select(. != ""))')
+          echo "charts=$charts" >> $GITHUB_OUTPUT
+
+    outputs:
+      charts: ${{ steps.build-matrix.outputs.charts }}
+
+  lint:
+    runs-on: ubuntu-latest
+    needs: [build-matrix]
+
+    strategy:
+      fail-fast: true
+      matrix:
+        chart: ${{ fromJson(needs.build-matrix.outputs.charts) }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # pin@v3
+        with:
+          fetch-depth: 0
+
+      - name: Check lock file updated
+        run: |
+          helm dependency update . && helm dependency build .
+          git diff --exit-code
+        working-directory: ${{ matrix.chart }}
+
   test:
     runs-on: ubuntu-latest
     steps: