Bump coverage from 5.0a1 to 7.3.1

Bumps [coverage](https://github.com/nedbat/coveragepy) from 5.0a1 to 7.3.1.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](https://github.com/nedbat/coveragepy/commits/7.3.1)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,7 +1,7 @@
 Authlib==0.8
 flask-session==0.4.0
 loginpass==0.1.1
-coverage==5.0a1
+coverage==7.3.1
 Flask==2.2.3
 Flask-Markdown==0.3
 Flask-WTF==1.0.1