no ff testing on linux

build/azure-pipelines/linux/continuous-build-linux.yml

@@ -50,7 +50,7 @@ steps:
     DISPLAY=:10 ./scripts/test.sh --tfs "Unit Tests"
   displayName: Run Unit Tests (Electron)
 - script: |
-    DISPLAY=:10 yarn test-browser --browser chromium --browser firefox
+    DISPLAY=:10 yarn test-browser --browser chromium
   displayName: Run Unit Tests (Browser)
 - script: |
     DISPLAY=:10 ./scripts/test-integration.sh --tfs "Integration Tests"

build/azure-pipelines/linux/product-build-linux.yml

@@ -123,7 +123,7 @@ steps:
 
 - script: |
     set -e
-    DISPLAY=:10 yarn test-browser --build --browser chromium --browser firefox
+    DISPLAY=:10 yarn test-browser --build --browser chromium
   displayName: Run unit tests (Browser)
   condition: and(succeeded(), eq(variables['VSCODE_STEP_ON_IT'], 'false'))