Use mock from Python stdlib and upgrade test requirements versions

[dbast]

Description

mock is part of the Python standard lib since Python 3.3, see also https://docs.python.org/3/library/unittest.mock.html. Switching to that allows to remove it from test/requirements.txt.

While at it, also updating the package versions in test/requirements.txt.

This pull request is categorized as a:

• [ ] New feature
• [ ] Bug fix
• [ ] Code refactor
• [ ] Documentation
• [x] Other

Checklist

• [ ] I’ve run pytest and made sure all unit tests pass before sumbitting the PR

If you modified or added functionality/workflow, did you add new unit tests?

• [ ] No, I’m a fool
• [ ] Yes
• [x] N/A

I have tested this PR on the following platforms/os:

• [ ] Raspberry Pi OS Manual Build
• [ ] SeedSigner OS on a Pi0/Pi0W board
• [ ] Other

Note: Keep your changes limited in scope; if you uncover other issues or improvements along the way, ideally submit those as a separate PR. The more complicated the PR the harder to review, test, and merge.

[jdlcdl]

Seems safe enough to me.

ACK tested

• no problems re-installing requirements on linux desktop and raspi-os on pi2
• no problems running test suite on both above

[kdmukai]

Tested ACK.

Full test suite has no complaints (coverage run -m pytest). Screenshot generator has no complaints (pytest tests/screenshot_generator/generator.py)

Ran the tests in local dev virtualenv on macOS.

[newtonick]

ACK Tested on RaspiOS local dev build and on macOS.