ci(test.yaml): add workflow_dispatch

Author: aleaf

.github/workflows/test.yaml

@@ -7,7 +7,8 @@ on:
     - cron: '0 9 * * 1' # run every Monday at 9 AM UTC (3 am PST)
   push:
   pull_request:
-
+  workflow_dispatch:
+  
 jobs:
   build:
     name: ${{ matrix.python-version }}, ${{ matrix.os }}