docs: link the cropping tutorial from crop_coord, bump notebooks submodule

[timtreis]

Summary

• crop_coord docstring now links to the new cropping tutorial (docs: add cropping tutorial (crop_coord) spatialdata-plot-tutorials#25).
• Bumps docs/notebooks submodule from 8d786cf to notebooks main (c3ae9ba) — cosmetic, RTD and build.yaml already pull notebooks main with --remote.
• Lets ruff reorder one import in basic.py (pre-existing isort drift on main).

No gallery/thumbnail changes needed here: docs/gallery.md includes the card grids from notebooks/tutorials/index.md / notebooks/examples/index.md, and :img-top: /notebooks/_static/img/*.png resolves through the submodule (verified on the live site for as_points / marker_shapes).

Note on hooks

CI has no pre-commit job; main currently fails the local mypy hook (17 errors in _geometry.py, _color.py, render.py, basic.py, unrelated to this PR). Committed with SKIP=mypy. Worth a separate lint job or pre-commit.ci.

🤖 Generated with Claude Code

https://claude.ai/code/session_011JMbY8asahxaytthjvCKDv

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.09%. Comparing base (9f19b7d) to head (672bb45).

Additional details and impacted files

@@ Coverage Diff @@## main #773 +/- ##
=======================================
Coverage 80.09% 80.09% =======================================
Files 18 18 Lines 4863 4863 Branches 1080 1080 =======================================
Hits 3895 3895 Misses 603 603 Partials 365 365 

Files with missing lines	Coverage Δ
src/spatialdata_plot/pl/basic.py	83.29% <ø> (ø)

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