Add ci job for releasing to winget

.github/workflows/win-exe.yml

@@ -413,3 +413,21 @@ jobs:
           username: ${{ secrets.ALLOWLIST_AVAST_USERNAME }}
           password: ${{ secrets.ALLOWLIST_AVAST_PASSWORD }}
           local-dir: files/
+  notify-winget:
+    name: Notify for winget-release
+    if: startsWith(github.ref, 'refs/tags/')
+    needs: [build-msi]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Slack Notification
+        uses: rtCamp/action-slack-notify@v2
+        env:
+          SLACK_WEBHOOK: ${{ secrets.SLACK_WEBHOOK_URL }}
+          SLACK_USERNAME: 'Cryptobot'
+          SLACK_ICON: false
+          SLACK_ICON_EMOJI: ':bot:'
+          SLACK_CHANNEL: 'cryptomator-desktop'
+          SLACK_TITLE: "MSI of ${{ github.event.repository.name }} ${{ github.event.release.tag_name }} published."
+          SLACK_MESSAGE: "Ready to <https://github.com/${{ github.repository }}/actions/workflows/winget.yml| release to winget>."
+          SLACK_FOOTER: false
+          MSG_MINIMAL: true