dev: sync nix and pixi dev env versions

[li-em]

• nix flake update
• sync pixi and nix versions, using nix as the reference
• drop Ian's hypothesis fork, there were many changes to hypothesis since it was forked

[codecov-commenter]

Codecov Report

❌ Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.00%. Comparing base (07c2e55) to head (7f670f2).

Files with missing lines	Patch %	Lines
icechunk/src/storage/redirect.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2352      +/-   ##
==========================================
+ Coverage   84.37%   85.00%   +0.63%     
==========================================
  Files          88       88              
  Lines       39611    39609       -2     
==========================================
+ Hits        33421    33669     +248     
+ Misses       6190     5940     -250     

Flag	Coverage Δ
python	90.09% <ø> (?)
rust	84.41% <66.66%> (+0.03%)	⬆️

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