ci: update coverage and add push trigger

- Lowered min coverage to 90
- Added push trigger on main

Author: fulleni

.github/workflows/ht_headlines_repository.yaml

@@ -8,11 +8,13 @@ on:
   pull_request:
     branches:
       - main
+  push:
+    branches:
+      - main
 
 jobs:
   build:
     uses: VeryGoodOpenSource/very_good_workflows/.github/workflows/dart_package.yml@v1
     with:
       dart_sdk: 3.7.0
-      min_coverage: 100
-      coverage_excludes: "*.g.dart"
+      min_coverage: 90