ci: add CodeQL workflow (#178)

This PR adds a workflow that runs the CodeQL analyzer on each push and
PR, and also on a daily basis.

.github/workflows/codeql.yml

@@ -0,0 +1,43 @@
+name: "codeql-scanning"
+
+on:
+  push:
+    branches:
+      - main
+      - 'release/*'
+  pull_request:
+    branches:
+      - main
+      - 'release/*'
+  schedule:
+    - cron: '0 9 * * *'
+
+jobs:
+  CodeQL-Build:
+    runs-on: ubuntu-latest
+
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+      pull-requests: read
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+      with:
+        submodules: recursive
+
+    - name: Install golang
+      uses: actions/setup-go@v5
+      with:
+        go-version: '1.21.13'
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v3
+      with:
+        languages: go
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v3