Change the `typer[all]` dependency to `typer-slim[standard]`

[musicinmybrain]

In 0.12.1, Typer was significantly reorganized.

• typer-slim is the library (for import typer)
• typer-slim[standard] adds optional dependencies (currently rich and shellingham, basically equivalent to the old typer[all])
• typer-cli is the typer command-line tool
• typer is now basically a metapackage that brings in all of the above, and it no longer has an all extra

Pip will warn about this and proceed,

WARNING: typer 0.12.1 does not provide the extra 'all'

but there are other tools that will fail hard when asked to resolve a (now) nonexistent extra.

Since this project doesn’t need the typer command-line tool, it looks like changing the dependency to typer-slim[standard] is the best way forward.

See https://typer.tiangolo.com/release-notes/#0121 and https://github.com/tiangolo/typer/discussions/785 for further discussion and details.

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I am the maintainer of the python-typer package in Fedora Linux, and I’m trying to get everything that depends on it to be compatible with this reorganization so I can update it.

I tested this PR by pip install -e .[tests] in a virtualenv, followed by running python -m pytest and trying a few of the Basic usage – command line interface examples and confirming that the output was still “pretty,” with box-drawing, colors, and so on.

[hoechenberger]

Thank you, @musicinmybrain!