MNT: (deps): Bump pytest from 6.0.0 to 6.0.1 in /ci

Bumps [pytest](https://github.com/pytest-dev/pytest) from 6.0.0 to 6.0.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.0.0...6.0.1)

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

ci/test_requirements.txt

@@ -1,4 +1,4 @@
-pytest==6.0.0
+pytest==6.0.1
 pytest-cov==2.10.0
 pytest-mpl==0.11
 netCDF4==1.5.3