Bump py from 1.8.0 to 1.10.0 in /docs

Bumps [py](https://github.com/pytest-dev/py) from 1.8.0 to 1.10.0.
- [Release notes](https://github.com/pytest-dev/py/releases)
- [Changelog](https://github.com/pytest-dev/py/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/py@1.8.0...1.10.0)

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

docs/requirements.txt

@@ -57,7 +57,7 @@ pluggy==0.9.0
 prometheus-client==0.6.0
 prompt-toolkit==2.0.9
 ptyprocess==0.6.0
-py==1.8.0
+py==1.10.0
 pygments==2.3.1
 pyparsing==2.4.0
 pyrsistent==0.14.11