feat: numpy 2.x compatibility

[filimarc]

Summary

• Replace np.array with np.asarray across bsb-core and bsb-hdf5 (numpy 2.0 changed copy=False semantics)
• Replace removed np.float_ alias with np.float64 in arborize
• Remove np.VisibleDeprecationWarning usage in tests (removed in numpy 2.0)
• Loosen numpy pins from ~=1.x to >=1.x in bsb-core, bsb-arbor, arborize, nrn-patch
• Loosen quantities pin to >=0.15.0 to allow 0.16.x (required by elephant 1.2.0)
• Bump internal lib pins to ~=7.4 in bsb-otel, arborize, sphinxext-bsb

close #237

Test plan

• CI passing on Python 3.10 and 3.12

Generated with Claude Code

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📚 Documentation preview 📚: https://nrn-patch--240.org.readthedocs.build/en/240/

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📚 Documentation preview 📚: https://arborize--240.org.readthedocs.build/en/240/

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📚 Documentation preview 📚: https://bsb-otel--240.org.readthedocs.build/en/240/

[codecov]

Codecov Report

❌ Patch coverage is 96.96970% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 82.89%. Comparing base (80ffbd5) to head (127163e).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/bsb-core/bsb/storage/_chunks.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #240      +/-   ##
==========================================
+ Coverage   80.54%   82.89%   +2.34%     
==========================================
  Files         188      135      -53     
  Lines       18179    15414    -2765     
  Branches     2174     1834     -340     
==========================================
- Hits        14642    12777    -1865     
+ Misses       2977     2195     -782     
+ Partials      560      442     -118     

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