ci: Add CodeQL config (#39)

.github/workflows/codeql.yml

@@ -0,0 +1,46 @@
+name: Analyze
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  analyze:
+    name: CodeQL
+    strategy:
+      matrix:
+        include:
+          - language: csharp
+            build-mode: autobuild
+
+    runs-on: ubuntu-latest
+    permissions:
+      # required for all workflows
+      security-events: write
+
+      # required to fetch internal or private CodeQL packs
+      packages: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup dotnet
+        uses: actions/setup-dotnet@v3
+        with:
+          dotnet-version: 9.x
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v3
+        with:
+          languages: ${{ matrix.language }}
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v3
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v3
+        with:
+          category: "/language:${{matrix.language}}"