fix(ci): Discord pre-release notification should happen when on dev

Pre-release only happen when on the `dev` branch, so the job is skipped under condition `if: github.event.release.target_commitish == 'main'`

Hence, change `main` --> `dev`

Author: LittleCoinCoin

.github/workflows/prerelease-discord-notification.yml

@@ -7,7 +7,7 @@ on:
 jobs:
   notify-discord:
     runs-on: ubuntu-latest
-    if: github.event.release.target_commitish == 'main'
+    if: github.event.release.target_commitish == 'dev'
     steps:
       - name: Send Discord Pre-release Notification
         uses: sarisia/actions-status-discord@v1