bazel_worker: Fix broken bad action (#1680)

Author: kevmoo

.github/workflows/bazel_worker.yaml

@@ -38,6 +38,6 @@ jobs:
           sdk: ${{ matrix.sdk }}
       - run: dart pub get
       - run: "dart format --output=none --set-exit-if-changed ."
-        if: ${{ matrix.sdk == dev }}
+        if: ${{ matrix.sdk == 'dev' }}
       - name: Test
         run: ./tool/travis.sh