Bump coverage from 5.2.1 to 6.2 in /compilesketches

Bumps [coverage](https://github.com/nedbat/coveragepy) from 5.2.1 to 6.2.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-5.2.1...6.2)

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

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

Author: dependabot[bot]

compilesketches/tests/requirements.txt

@@ -1,4 +1,4 @@
 --requirement ../requirements.txt
-coverage==5.2.1
+coverage==6.2
 pytest==5.4.2
 pytest-mock==3.1.0