[Python 3.11.2 Upgrade] Updated Dockerfile and Requirements

[BethanyG]

This upgrade should happen at the same time for the Test Runner, Analyzer, & Representer
After these three are merged, the updates to the track CI and Content should be merged.

• Updated Dockerfile to use python:3.11.2-slim
• Updated Requirements.txt
  • pytest~=7.2.2 🎉
  • pytest-subtests~=0.10.0
• Changed pytest.ini file (color codes were breaking the golden tests)
  • addopts = --color=no
  • console_output_style =classic
• Changed the runner __init__.py file to strip new subtest fail inserts where possible.
• Regenerated 6 Golden Test results.json, due to changes in Python 3.11 output.

[BethanyG]

@ErikSchierboom & @iHiD - tagging you both, as this is an upgrade to a new version of Python. Given the upgrades done by the R track and the Go track, this one may be cursed as well. 😱 🤞🏽 that we are lucky here, and slide into production without issue. 😁

All tests against exercises and golden files do pass, and I have had zero issues on my machine when testing. As promised by the Python Dev team, this release does indeed feel speedy.

Changes to the track CI were .. bumpy ... but are resolved. Documentation updates are still pending, and should be done by the EOD/Monday latest.

[ErikSchierboom]

LGTM