chore(deps): bump apprise from 1.9.9 to 1.10.0 in /backend (#236)

Bumps [apprise](https://github.com/caronc/apprise) from 1.9.9 to 1.10.0.
- [Release notes](https://github.com/caronc/apprise/releases)
- [Commits](https://github.com/caronc/apprise/compare/v1.9.9...v1.10.0)

---
updated-dependencies:
- dependency-name: apprise
  dependency-version: 1.10.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/requirements.txt

@@ -41,7 +41,7 @@ redis==7.4.0
 cryptography==48.0.0  # Updated: Fixed NULL pointer dereference (was 42.0.0)
 
 # Notifications
-apprise==1.9.9
+apprise==1.10.0
 
 # Monitoring & Logging
 prometheus-client==0.25.0