feat(ci): CodeQL workflow

- runs on push, PR, schedule
- checks JS and Python when included in changes

Author: thekaveman

.github/workflows/codeql.yml

@@ -0,0 +1,67 @@
+# https://codeql.github.com/
+name: CodeQL
+
+on:
+  push:
+    paths:
+      - "**.js"
+      - "**.py"
+  pull_request:
+    branches: [main]
+    paths:
+      - "**.js"
+      - "**.py"
+  schedule:
+    - cron: "24 9 * * 6"
+
+jobs:
+  setup:
+    name: Set up CodeQL analysis
+    runs-on: ubuntu-latest
+    # Required permissions
+    permissions:
+      pull-requests: read
+    outputs:
+      # changes is a JSON array with names of all filters matching any of the changed files
+      languages: ${{ steps.filter.outputs.changes }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            javascript: "**.js"
+            python: "**.py"
+
+  codeql:
+    name: CodeQL Analyze
+    runs-on: ubuntu-latest
+    needs: setup
+    if: ${{ needs.setup.outputs.languages != '[]' }}
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        # Parse JSON array containing names of all filters matching any of changed files
+        # e.g. ['javascript', 'python'] if both file types had changes
+        language: ${{ fromJSON(needs.setup.outputs.languages) }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: ${{ matrix.language }}
+          # https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning#specifying-configuration-details-using-the-config-input
+          config: |
+            paths-ignore:
+              - tests
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v3