Upgrade pytest and minor dependencies

[conatus]

pytest the Python testing library depends upon a library called py. This library has a very minor and near impossible to exploit vulnerability in it. However, this vulnerablity has been given a CVE which means it is marked as serious and blocks our deploy pipeline.

The authors of pytest have removed py and "vendored" it, meaning they've taken the functionality they need into their main package and removed the need for this dependency. Thus avoiding the (false) CVE now and in future.

See for more dertails:

• ReDoS vulnerability in svnurl.py pytest-dev/py#287 (comment)
• CVE-2022-42969: security issue in library py used by this project pytest-dev/pytest#10392

This upgrades pytest to the latest version. The tests, such as they are, run, which means that this is a safe update.

Currently the pipelines on #50, #49, #41 at minimum are not completing due to this issue.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I've checked the spec (e.g. Figma file) and documented any divergences.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I've updated the documentation accordingly.
• Replace unused checkboxes with bullet points.