Use up to date firehose in publish (#376)

Author: mosuem

.github/workflows/publish.yaml

@@ -130,7 +130,7 @@ jobs:
           sdk: ${{ inputs.sdk }}
 
       - name: Install firehose
-        run: dart pub global activate firehose
+        run: dart pub global activate --source git https://github.com/dart-lang/ecosystem --git-path pkgs/firehose/
         if: ${{ !inputs.local_debug }}
 
       - name: Install local firehose