Compatibility with Python 3.13 and modern versions of dependencies.

[sna-scourtney]

• ADDED: Compatible with Python 3.13. This required updating Typer, Click, click-shell, and other dependencies to versions that support Python 3.13. This is a BREAKING CHANGE for projects that are tied to older versions of those dependencies, because some of the libraries' API signatures changed.
• ADDED: More complete project definition in pyproject.toml to take better advantage of Poetry and other build tools. requirements.txt is now only comments, with all dependencies declared in pyproject.toml.
• DROPPED: Dropped support for Python 3.8.x which is officially EOL.
• FIXED: make_typer_shell() was returning None but was expected by callers to return the Typer instance.
• FIXED: Incorrect typing of some variables and function parameters.
• EDITED: Corrected some typos in comments and string literals. Formatted some one-line function calls to multi-line to match the style of the rest of the code and to make demo.py more approachable for newcomers.
• KNOWN ISSUE: The "magic rainbow" panel is not working.

I am submitting this PR as a draft for comment and early review and in hope that other eyes will spot the problem with the "magic rainbow" panel.

[sna-scourtney]

I had missed one occurrence of that get_command() method being called. I am not 100% certain I've captured the original behavior of typer_shell with respect to this, so please review and correct if needed.

[sna-scourtney]

I reviewed the source of click and (previous) typer-shell in more detail, and I believe this now closely matches the original intent.

This is probably still not ready for merge, but I think it's ready for upstream review.

[sna-scourtney]

Build result:

$ poetry build
Building typer-shell (0.2.0)
Building sdist
  - Building sdist
  - Built typer_shell-0.2.0.tar.gz
Building wheel
  - Building wheel
  - Built typer_shell-0.2.0-py3-none-any.whl

[FergusFettes]

Thanks for this! Will review in the next few days.

[sna-scourtney]

Thanks for this! Will review in the next few days.

Much appreciated! In my project I was getting an empty red error box that I assumed was the fault of my code. That was the main reason for marking the PR as Draft. I've just learned this is a known issue with Typer when used with Click 8.2.0 or later. It's discussed in PR 1240 for Typer.

Since I now know it's not my code causing that problem, I'm a little more confident of my own PR here.

[FergusFettes]

merged this and added some more stuff :).