Allow schema generation on-demand (#15885)

Author: AlanCoding

.github/workflows/upload_schema.yml

@@ -5,6 +5,7 @@ env:
   LC_ALL: "C.UTF-8" # prevent ERROR: Ansible could not initialize the preferred locale: unsupported locale setting
 
 on:
+  workflow_dispatch:
   push:
     branches:
       - devel