Change container build action to manual dispatch

.github/workflows/build-container.yml

@@ -1,9 +1,6 @@
 name: Build and Push Docker Image
 
-on:
-  push:
-    branches:
-      - main
+on: workflow_dispatch
 
 permissions:
   contents: read
@@ -120,4 +117,4 @@ jobs:
           untagged: true
           # Optional: Keep the most recent untagged if needed, 
           # otherwise 0 deletes all untagged.
-          keep-last: 0
+          keep-last: 0