ci: run either on OR or push but only when Run-Checks is specified

.gitea/workflows/ci.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
       branches:
         - main
+  push:
+    branches-ignore:
+      - main
+
 jobs:
   run-ci-linux:
     runs-on: ubuntu-latest
@@ -11,7 +15,8 @@ jobs:
     # push with commit containing "Run-Checks"
     if: >
       (contains(github.event.head_commit.message, 'Run-Checks') &&
-      github.event_name == 'push')
+      github.event_name == 'push') ||
+      github.event_name == 'pull_request'
     steps:
       - name: Check out repository code
         uses: actions/checkout@v3