Skip CodeQL Python job when no Python sources are present

.github/workflows/codeql.yml

@@ -0,0 +1,60 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+  schedule:
+    - cron: "0 4 * * 0"
+
+permissions:
+  contents: read
+
+jobs:
+  detect-languages:
+    name: Detect CodeQL languages
+    runs-on: ubuntu-latest
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Build language matrix
+        id: set-matrix
+        run: |
+          include='[{"language":"actions","build-mode":"none"}]'
+
+          if git ls-files '*.py' | grep -q .; then
+            include='[{"language":"actions","build-mode":"none"},{"language":"python","build-mode":"none"}]'
+          fi
+
+          echo "matrix={\"include\":$include}" >> "$GITHUB_OUTPUT"
+
+  analyze:
+    name: Analyze (${{ matrix.language }})
+    needs: detect-languages
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJSON(needs.detect-languages.outputs.matrix) }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v4
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: ${{ matrix['build-mode'] }}
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v4
+        with:
+          category: /language:${{ matrix.language }}