Make zip strict in apply_function_over_dataset

[ricardoV94]

We wasted some time debugging stuff because of this :)

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📚 Documentation preview 📚: https://pymc--7485.org.readthedocs.build/en/7485/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.16%. Comparing base (0680957) to head (4b527ca).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7485      +/-   ##
==========================================
- Coverage   92.17%   92.16%   -0.01%     
==========================================
  Files         103      103              
  Lines       17216    17221       +5     
==========================================
+ Hits        15868    15872       +4     
- Misses       1348     1349       +1     

Files with missing lines	Coverage Δ
pymc/backends/arviz.py	96.61% <100.00%> (ø)

... and 2 files with indirect coverage changes