Fix broken import of sp_sum

[PatrickRobotham]

sp_sum has been moved in pytensor from pytensor.sparse.basic to pytensor.sparse.math

The higher level module pytensor.sparse exports this function.

Description

Related Issue

• [x] Closes #7983
• [ ] Related to #

Checklist

• [x] Checked that the pre-commit linting/style checks pass
• [ ] Included tests that prove the fix is effective or that the new feature works
• [ ] Added necessary documentation (docstrings and/or example notebooks)
• [ ] If you are a pro: each commit corresponds to a relevant logical change

Type of change

• [ ] New feature / enhancement
• [x] Bug fix
• [ ] Documentation
• [ ] Maintenance
• [ ] Other (please specify):

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 91.49%. Comparing base (87f80f9) to head (ef352dc).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7984   +/-   ##
=======================================
  Coverage   91.49%   91.49%           
=======================================
  Files         116      116           
  Lines       18963    18964    +1     
=======================================
+ Hits        17350    17351    +1     
  Misses       1613     1613           

Files with missing lines	Coverage Δ
pymc/distributions/multivariate.py	93.92% <100.00%> (+<0.01%)	:arrow_up:

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[ricardoV94]

Didn't notice the open PR, I left a comment on the original issue. PyMC main should be compatible with the pinned PyTensor dependency not its main branch. We'll be doing a new PyTensor release soon and follow with update on the PyMC side