ci: allow release drafter to be trigger manually

in cases where we ran it before removing tags

Author: tekumara

.github/workflows/drafter.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+  workflow_dispatch:
   # required only for autolabeler
   pull_request_target:
     types: [opened, reopened, synchronize]