Update coverage requirement in /tools

Updates the requirements on [coverage](https://github.com/nedbat/coveragepy) to permit the latest version.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-4.4.2...7.6.10)

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

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

tools/constraints.txt

@@ -8,7 +8,7 @@ pytest>=5.0,<8.4
 protobuf>=3.18.1,<4.0.0
 defusedxml>=0.7.1
 requests>=2.25.1
-coverage>=4.4.2,<=7.0.5
+coverage>=4.4.2,<=7.6.10
 astroid>=2.9.0
 pylint>=2.7.0
 pyenchant>=3.0.0