ci: add weekly-only CodeQL workflow to replace default setup

Author: GeiserX

.github/workflows/codeql.yml

@@ -0,0 +1,21 @@
+name: CodeQL
+
+on:
+  schedule:
+    - cron: '0 6 * * 1'
+  workflow_dispatch:
+
+permissions:
+  security-events: write
+  contents: read
+
+jobs:
+  analyze:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: github/codeql-action/init@v3
+        with:
+          languages: swift
+      - uses: github/codeql-action/autobuild@v3
+      - uses: github/codeql-action/analyze@v3