Update dependency pytest-cov to v4

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
pytest-cov (changelog)	==3.0.0 -> ==4.0.0

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Release Notes

pytest-dev/pytest-cov

v4.0.0

Compare Source

Note that this release drops support for multiprocessing.

• --cov-fail-under no longer causes pytest --collect-only to fail
  Contributed by Zac Hatfield-Dodds in #&#8203;511 <https://github.com/pytest-dev/pytest-cov/pull/511>_.

• Dropped support for multiprocessing (mostly because issue 82408 <https://github.com/python/cpython/issues/82408>_). This feature was
  mostly working but very broken in certain scenarios and made the test suite very flaky and slow.

  There is builtin multiprocessing support in coverage and you can migrate to that. All you need is this in your
  .coveragerc::

  [run]
  concurrency = multiprocessing
  parallel = true
  sigterm = true

• Fixed deprecation in setup.py by trying to import setuptools before distutils.
  Contributed by Ben Greiner in #&#8203;545 <https://github.com/pytest-dev/pytest-cov/pull/545>_.

• Removed undesirable new lines that were displayed while reporting was disabled.
  Contributed by Delgan in #&#8203;540 <https://github.com/pytest-dev/pytest-cov/pull/540>_.

• Documentation fixes.
  Contributed by Andre Brisco in #&#8203;543 <https://github.com/pytest-dev/pytest-cov/pull/543>_
  and Colin O'Dell in #&#8203;525 <https://github.com/pytest-dev/pytest-cov/pull/525>_.

• Added support for LCOV output format via --cov-report=lcov. Only works with coverage 6.3+.
  Contributed by Christian Fetzer in #&#8203;536 <https://github.com/pytest-dev/pytest-cov/issues/536>_.

• Modernized pytest hook implementation.
  Contributed by Bruno Oliveira in #&#8203;549 <https://github.com/pytest-dev/pytest-cov/pull/549>_
  and Ronny Pfannschmidt in #&#8203;550 <https://github.com/pytest-dev/pytest-cov/pull/550>_.

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[codecov]

Codecov Report

Merging #412 (4a47a20) into main (22df8d2) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #412   +/-   ##
=======================================
  Coverage   95.45%   95.45%           
=======================================
  Files           5        5           
  Lines         308      308           
  Branches       43       43           
=======================================
  Hits          294      294           
  Misses          7        7           
  Partials        7        7