Bump coverage from 6.2 to 7.3.0

Bumps [coverage](https://github.com/nedbat/coveragepy) from 6.2 to 7.3.0.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@6.2...7.3.0)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -7,7 +7,7 @@ certifi==2021.10.8
 cffi==1.15.0
 chardet==4.0.0
 click==8.0.3
-coverage==6.2
+coverage==7.3.0
 dnspython==2.2.0
 email-validator==1.1.3
 flake8==3.8.4