Bump pytest from 6.2.2 to 6.2.3 (#300)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 6.2.2 to 6.2.3.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.2.2...6.2.3)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements_dev.txt

@@ -6,7 +6,7 @@ m2r==0.2.1
 mypy==0.812
 pip
 pytest-runner==5.3.0
-pytest==6.2.2
+pytest==6.2.3
 recommonmark==0.7.1
 Sphinx==3.5.3
 twine==3.4.1