Allow running pipelines without merge request

This will allow me to pass CI checks without creating merge requests,
since I work alone there is no point in them.

.github/workflows/go.yml

@@ -2,7 +2,7 @@ name: Go
 
 on:
   push:
-    branches: [ "main" ]
+    branches:
   pull_request:
     branches: [ "main" ]