fix: publish tutorials dependencies as PEP 621 extras - #885

What changes were proposed in this pull request?

• python/pyproject.toml: declare click, py7zr and requests in [project.optional-dependencies] as the tutorials extra (plus an all alias), with the same version constraints they already had. The existing [tool.poetry.group.tutorials.dependencies] group is left in place so poetry install --with tutorials keeps working for contributors and the docs in 01-contributing-guide.md stay accurate.
• python/poetry.lock: regenerated (Poetry 2.4.1) — marker/group metadata only, no package version changes.
• python/graphframes/console.py: catch the ImportError in main() and log a message that names the extra, instead of letting the console script die with a bare traceback.

all repeats the requirement list rather than referencing graphframes-py[tutorials] because Poetry refuses to lock a self-referential extra (Package 'graphframes-py[tutorials]' is listed as a dependency of itself).

Why are the changes needed?

Fixes #884.

Poetry dependency groups are a local dev-environment feature — Poetry never writes them into built distribution metadata. Only [project.optional-dependencies] (PEP 621) or [tool.poetry.extras] emit Provides-Extra / Requires-Dist … ; extra == "…". So the published graphframes_py-0.12.1-py3-none-any.whl has zero Requires-Dist and zero Provides-Extra lines, while still installing an unconditional console script:

[console_scripts]
graphframes=graphframes.console:main

console.py imports click at module scope and graphframes/tutorials/download.py imports py7zr and requests, so the shipped graphframes binary is broken for everyone, and there is no extra to install that fixes it.

Before, on a clean venv:

$ pip install 'graphframes-py[tutorials]'
WARNING: graphframes-py 0.12.1 does not provide the extra 'tutorials'
$ graphframes
Traceback (most recent call last):
  ...
  File ".../graphframes/console.py", line 1, in <module>
    import click
ModuleNotFoundError: No module named 'click'

After, building the wheel from this branch:

$ unzip -p dist/graphframes_py-*.whl '*/METADATA' | grep -E '^(Requires-Dist|Provides-Extra)'
Provides-Extra: all
Provides-Extra: tutorials
Requires-Dist: click (>=8.1.8,<9.0.0) ; extra == "all"
Requires-Dist: click (>=8.1.8,<9.0.0) ; extra == "tutorials"
Requires-Dist: py7zr (>=0.22.0,<0.23.0) ; extra == "all"
Requires-Dist: py7zr (>=0.22.0,<0.23.0) ; extra == "tutorials"
Requires-Dist: requests (>=2.33.0,<3.0.0) ; extra == "all"
Requires-Dist: requests (>=2.33.0,<3.0.0) ; extra == "tutorials"

$ pip install 'graphframes_py-*.whl[tutorials]'
$ graphframes
Usage: graphframes [OPTIONS] COMMAND [ARGS]...

  GraphFrames CLI: a collection of commands for graphframes.

Options:
  --help  Show this message and exit.

Commands:
  stackexchange  Download Stack Exchange archive for a given SUBDOMAIN.

And without the extra, the failure is now actionable rather than a traceback:

$ pip install 'graphframes_py-*.whl'
$ graphframes
The `graphframes` CLI requires the optional `tutorials` dependencies, which are not installed. Install them with: pip install 'graphframes-py[tutorials]' (No module named 'click')
$ echo $?
1

Note on #881

#881 landed the lazy import in console.py but its pyproject.toml half was reverted, on the grounds that click "belongs under tutorials, since it is required for the CLI" and shouldn't become a separate one-package group. This PR keeps that structure — all three packages stay together under tutorials — and only changes where they are declared so they actually reach the published metadata. No new runtime dependency is added to the base install.

pyspark remains undeclared, unchanged by this PR.