Removes unused Flutter output

Author: zgosalvez

.github/workflows/ci.yml

@@ -23,8 +23,6 @@ jobs:
     strategy:
       matrix:
         category: [static, unit, widget]
-    outputs:
-      flutter_version: ${{ steps.get-flutter-version.outputs.version }}
     steps:
     - name: Clone the repository
       uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f # v2.3.4