Replace magic comment with workflow_dispatch

.github/workflows/deploy.yml

@@ -1,16 +1,9 @@
 on:
-  issue_comment:
-    types: [created]
+  workflow_dispatch: {}
   repository_dispatch:
     types: [published]
 jobs:
   deploy:
-    if: |
-      github.event_name == 'repository_dispatch' ||
-      github.event_name == 'issue_comment'
-        && github.event.issue.number == 1
-        && (github.actor == 'andrewbranch' || github.actor == 'sandersn')
-        && startsWith(github.event.comment.body, '/deploy publisher')
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2