ci: run CI on PRs

Author: TheDevMinerTV

.github/workflows/ghcr.yml

@@ -1,9 +1,11 @@
 name: Build and publish Docker image
 
 on:
-  workflow_dispatch:
+  release:
+    types: [published]
   schedule:
     - cron: "0 0 * * 0"
+  pull_request:
   push:
     branches:
       - master