ci(rultor): update Flutter docker image

Closes #157

Author: rafamizes

.github/workflows/build.yml

@@ -7,10 +7,9 @@ on:
   # Triggers the workflow on push or pull request events but only for the main branch
   # Runs this action when you push on master
   push:
-    branches: [ "master" ]
+    branches: [master]
   # Runs this when a PR against master is created
   pull_request:
-    branches: [ "master" ]
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
@@ -55,5 +54,6 @@ jobs:
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v4
         with:
+          fail_ci_if_error: true
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./coverage/lcov.info

.rultor.yml

@@ -1,5 +1,5 @@
 docker:
-  image: cirrusci/flutter:stable
+  image: ghcr.io/cirruslabs/flutter:stable
   as_root: true
 architect:
   - rafamizes