build(deps): bump dawidd6/action-send-mail in the github-actions group

Bumps the github-actions group with 1 update: [dawidd6/action-send-mail](https://github.com/dawidd6/action-send-mail).


Updates `dawidd6/action-send-mail` from 3.12.0 to 18
- [Release notes](https://github.com/dawidd6/action-send-mail/releases)
- [Commits](dawidd6/action-send-mail@v3.12.0...v18)

---
updated-dependencies:
- dependency-name: dawidd6/action-send-mail
  dependency-version: '18'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/push-email-notify.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Send push notification email
-        uses: dawidd6/action-send-mail@v3.12.0
+        uses: dawidd6/action-send-mail@v18
         with:
           server_address: ${{ secrets.SMTP_HOST }}
           server_port: ${{ secrets.SMTP_PORT }}