Safeguard against invalid user input in render_shapes

[timtreis]

No description provided.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 82.35294% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.34%. Comparing base (64aeb73) to head (95bbb07).

Files with missing lines	Patch %	Lines
src/spatialdata_plot/pl/utils.py	82.35%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #512      +/-   ##
==========================================
- Coverage   83.37%   83.34%   -0.03%     
==========================================
  Files           8        8              
  Lines        2334     2384      +50     
==========================================
+ Hits         1946     1987      +41     
- Misses        388      397       +9     

Files with missing lines	Coverage Δ
src/spatialdata_plot/pl/utils.py	79.69% <82.35%> (+0.08%)	⬆️

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[timtreis]

@josenimo could you rerun with this branch? What do you think of the error that is now returned?