Update trigger-homebrew-update.yml [skip ci]

.github/workflows/trigger-homebrew-update.yml

@@ -3,6 +3,9 @@ on:
   release:
     types: [published]
 
+  # Allows manual triggering of the workflow
+  workflow_dispatch:
+
 jobs:
   trigger-tap-update:
     runs-on: ubuntu-latest
@@ -18,4 +21,4 @@ jobs:
               "release": {
                   "tag_name": "${{ github.event.release.tag_name }}"
               }
-            }
+            }