ci: add security policy, CodeQL scanning, enable Dependabot

.github/workflows/codeql.yml

@@ -0,0 +1,31 @@
+name: CodeQL
+
+on:
+  push:
+    branches:
+      - main
+      - dev
+  pull_request:
+    branches:
+      - main
+  schedule:
+    - cron: "0 6 * * 1"
+
+jobs:
+  analyze:
+    name: Analyze (Python)
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: python
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v3