Update codeql.yml

.github/workflows/codeql.yml

@@ -21,7 +21,7 @@ jobs:
       matrix:
         include:
         - language: csharp
-          build-mode: autobuild
+          build-mode: manual
     steps:
     - name: Checkout repository
       uses: actions/checkout@v4
@@ -33,6 +33,16 @@ jobs:
         languages: ${{ matrix.language }}
         build-mode: ${{ matrix.build-mode }}
 
+    - name: Build
+      shell: bash
+      run: |
+        echo 'If you are using a "manual" build mode for one or more of the' \
+          'languages you are analyzing, replace this with the commands to build' \
+          'your code, for example:'
+        echo '  make bootstrap'
+        echo '  make release'
+        exit 1
+
     - name: Perform CodeQL Analysis
       uses: github/codeql-action/analyze@v3
       with: