Update rc.yml

Author: lriggs

.github/workflows/rc.yml

@@ -17,6 +17,16 @@
 
 name: RC
 on:
+  workflow_dispatch:
+    inputs:
+      arrow_branch:
+        description: 'Arrow branch to build'
+        required: true
+      arrow_repo:
+        description: 'Arrow repository'
+        type: string
+        required: true
+        default: https://github.com/dremio/arrow.git
   push:
     branches:
       - "**"