separate coveralls and refine workflow triggers

.gitea/workflows/gen_code.yml

@@ -1,8 +1,8 @@
 name: Generate check
 
 on:
-  push:
   pull_request:
+    types: [opened, reopened, synchronize]
 
 jobs:
   check-changes:
@@ -24,7 +24,7 @@ jobs:
             echo "has_gen_changes=false" >> $GITHUB_OUTPUT
           fi
 
-  check-generate:
+  verify-generate:
     runs-on: ubuntu-latest
     needs: check-changes
     if: needs.check-changes.outputs.has_gen_changes == 'true'