Merge pull request rsim#2448 from yahonda/add_workflow_dispatch_to_ruby_head

Add `workflow_dispatch` to allow ruby_head action run manually

Author: yahonda

.github/workflows/ruby_head.yml

@@ -3,7 +3,7 @@ name: ruby_head
 on:
   schedule:
     - cron: "0 0 * * *"
-
+  workflow_dispatch:
 jobs:
   build:
     name: "ruby-${{ matrix.ruby }}-yjit-enabled: ${{ matrix.yjit-enabled }}"