Update TagBot.yml

Based on the instructions from https://discourse.julialang.org/t/ann-required-updates-to-tagbot-yml/49249.

Author: rikhuijzer

.github/workflows/TagBot.yml

@@ -2,8 +2,13 @@ name: TagBot
 on:
   schedule:
     - cron: 0 * * * *
+  issue_comment:
+    types:
+      - created
+  workflow_dispatch:
 jobs:
   TagBot:
+    if: github.event_name == 'workflow_dispatch' || github.actor == 'JuliaTagBot'
     runs-on: ubuntu-latest
     steps:
       - uses: JuliaRegistries/TagBot@v1