[PM-13271] Remove unused ci:coverage from gulpfile (#11455)

Remove the gulp coverage report since we now use jest, and coverage is handled through the root coverage report which is done in a different script.

.github/workflows/build-browser.yml

@@ -168,10 +168,6 @@ jobs:
         run: npm run dist:chrome:beta
         working-directory: browser-source/apps/browser
 
-      - name: Gulp
-        run: gulp ci
-        working-directory: browser-source/apps/browser
-
       - name: Upload Opera artifact
         uses: actions/upload-artifact@50769540e7f4bd5e21e526ee35c689e35e0d6874 # v4.4.0
         with:
@@ -235,14 +231,6 @@ jobs:
           path: browser-source.zip
           if-no-files-found: error
 
-      - name: Upload coverage artifact
-        if: false
-        uses: actions/upload-artifact@50769540e7f4bd5e21e526ee35c689e35e0d6874 # v4.4.0
-        with:
-          name: coverage-${{ env._BUILD_NUMBER }}.zip
-          path: browser-source/apps/browser/coverage/coverage-${{ env._BUILD_NUMBER }}.zip
-          if-no-files-found: error
-
   build-safari:
     name: Build Safari
     runs-on: macos-13