Rename TEST_MODE to specific variable for CodeQL Action

This allows us to set it automatically in the workflow generator,
simplifying things and reducing the scope for error.

.github/workflows/debug-artifacts.yml

@@ -45,6 +45,8 @@ jobs:
         - os: macos-latest
           version: nightly-latest
     name: Upload debug artifacts
+    env:
+      CODEQL_ACTION_TEST_MODE: true
     timeout-minutes: 45
     runs-on: ${{ matrix.os }}
     steps:
@@ -64,15 +66,11 @@ jobs:
           debug: true
           debug-artifact-name: my-debug-artifacts
           debug-database-name: my-db
-        env:
-          TEST_MODE: true
       - name: Build code
         shell: bash
         run: ./build.sh
       - uses: ./../action/analyze
         id: analysis  
-        env:
-          TEST_MODE: true
   download-and-check-artifacts:
     name: Download and check debug artifacts
     needs: upload-artifacts