Bump apprise from 1.7.2 to 1.7.3

Bumps [apprise](https://github.com/caronc/apprise) from 1.7.2 to 1.7.3.
- [Release notes](https://github.com/caronc/apprise/releases)
- [Commits](caronc/apprise@v1.7.2...v1.7.3)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,6 +1,6 @@
 --extra-index-url https://dl.cloudsmith.io/public/borgmatic-collective/borgmatic/python/simple/
 
-apprise==1.7.2
+apprise==1.7.3
 borgbackup==1.2.7
 borgmatic==1.8.8
 llfuse==1.5.0