Workaround for nan radii xenium

[LucaMarconato]

Relaxing and exception to a warning to be able to read and fix xenium data with radii being nan.

You can find more info here: #657

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.95%. Comparing base (e77f981) to head (923db85).
Report is 29 commits behind head on main.

Files with missing lines	Patch %	Lines
src/spatialdata/models/models.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #658      +/-   ##
==========================================
- Coverage   89.96%   89.95%   -0.02%     
==========================================
  Files          44       44              
  Lines        6769     6769              
==========================================
- Hits         6090     6089       -1     
- Misses        679      680       +1     

Files with missing lines	Coverage Δ
src/spatialdata/models/models.py	87.69% <0.00%> (-0.22%)	⬇️