Remove support for Python 3.7 and extend support to 3.12

[kieran-ryan]

🤔 What's changed?

Reverted required Python versions from 3.10+ back to 3.8+. Removed Python 3.7.

Added pipeline testing against Python 3.11 and 3.12.

⚡️ What's your motivation?

Support officially supported Python distributions, re-enabling 3.8 and 3.9; to support users appropriately.

➜  repository (main) python3.9 -m pip install cucumber-expressions==17.0.2
ERROR: Ignored the following versions that require a different python version: 17.0.1 Requires-Python >=3.10,<4.0; 17.0.2 Requires-Python >=3.10,<4.0
ERROR: Could not find a version that satisfies the requirement cucumber-expressions==17.0.2 (from versions: 16.0.0, 16.0.1, 16.1.0, 16.1.1, 16.1.2)
ERROR: No matching distribution found for cucumber-expressions==17.0.2

Fixes that test jobs with 3.8 and 3.9 were incorrectly running 3.10.

🏷️ What kind of change is this?

• 🐛 Bug fix (non-breaking change which fixes a defect)

♻️ Anything particular you want feedback on?

Python 3.7 was not being tested in the pipeline, is unsupported by our version of Poetry and has reached End of Life. Have removed support, let me know if any feedback on that decision.

If the activated Python version in the test job is below the required version of the package, poetry falls back on other installed versions (in this case 3.10). This presents a risk as the pipeline will pass if the required Python version is bumped and not failing for older Python versions still in the pipeline.

The currently activated Python version 3.8.18 is not supported by the project (^3.10).
Trying to find and use a compatible version. 
Using python3.10 (3.10.12)

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

[mpkorstanje]

LGTM, feel free to merge after applying the suggestion to the changelog.

Python 3.7 was not being tested in the pipeline, is unsupported by our version of Poetry and has reached End of Life. Have removed support, let me know if any feedback on that decision.

Usually, we only do the latest two stable releases. This avoids a plethora of CI jobs (and the potential headaches that come with having to support many versions). But supporting more versions is fine. As long as they're not EOL.

If the activated Python version in the test job is below the required version of the package, poetry falls back on other installed versions (in this case 3.10). This presents a risk as the pipeline will pass if the required Python version is bumped and not failing for older Python versions still in the pipeline.

I'm not sure I follow this. The matrix job should install only a single version of python. How can it fall back to a version that wasn't installed by the job?

[kieran-ryan]

If the activated Python version in the test job is below the required version of the package, poetry falls back on other installed versions (in this case 3.10). This presents a risk as the pipeline will pass if the required Python version is bumped and not failing for older Python versions still in the pipeline.

I'm not sure I follow this. The matrix job should install only a single version of python. How can it fall back to a version that wasn't installed by the job?

The ubuntu-latest GitHub runner uses Ubuntu 22.04, which packages Python 3.10.12.

Poetry was set to 3.10 upwards:

[tool.poetry.dependencies]
python = "^3.10"

And the test job was configured for Python 3.8-3.10.

python-version: ["3.8", "3.9", "3.10"]

However, rather than fail with 3.8 and 3.9, poetry looks for a compatible Python version, finding 3.10 of ubuntu-latest. As a result, each of the test jobs ran against 3.10 and passed - rather than fail for 3.8 and 3.9. Using a virtual environment should prevent this, however. See job #5715.

The currently activated Python version 3.8.18 is not supported by the project (^3.10).
Trying to find and use a compatible version. 
Using python3.10 (3.10.12)

[mpkorstanje]

Thanks for explaining! Very clear.