Deprecate redundant utilities for extracting constants

[ricardoV94]

Description

In PyTensor we have tho following similar utilities

1. pytensor.get_underlying_scalar_constant
2. pytensor.tensor.basic.get_underlying_scalar_constant_value
3. pytensor.tensor.basic.get_scalar_constant_value
4. pytensor.tensor.basic.extract_constant
5. pytensor.tensor.rewriting.math.get_constant

This PR removes and deprecates all except:

1. pytensor.tensor.basic.get_underlying_scalar_constant_value
2. pytensor.tensor.basic.get_scalar_constant_value

The reason for this distinction, is that the core utility, get_underlying_scalar_constant_value actually works for non-scalar inputs, if it can find a single scalar value underlies a potential n-dimensional tensor (say as in pt.zeros(5, 3, 2)). This is powerful, but can lead to subtle bugs when the caller forgets about it. This was the source of the bug behind #584 and was also likely present in other graphs such as gt(x, [0, 0, 0, 0]) and alike where the repeated condition broadcasts the output of the operation.

The utility get_scalar_constant_value raises if the input is not a scalar (ndim=0) type.

I don't love the underlying distinguishing the two. Perhaps unique would be better.

Both utilities now accept a raise_not_constant which when False (not-default) return the variable as is. I think I would prefer for it to return None but this requires less code changes.

Related Issue

• Closes local_add_neg_to_sub rewrite gives wrong results with negative constants #584
• Related to #

[codecov]

Codecov Report

Attention: Patch coverage is 86.99187% with 32 lines in your changes missing coverage. Please review.

Project coverage is 82.07%. Comparing base (0824dba) to head (8dcbc2b).

Files with missing lines	Patch %	Lines
pytensor/tensor/rewriting/math.py	74.02%	9 Missing and 11 partials ⚠️
pytensor/tensor/basic.py	88.00%	6 Missing ⚠️
pytensor/tensor/variable.py	85.71%	3 Missing ⚠️
pytensor/scan/rewriting.py	90.90%	0 Missing and 1 partial ⚠️
pytensor/tensor/rewriting/subtensor.py	80.00%	0 Missing and 1 partial ⚠️
pytensor/tensor/shape.py	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1046      +/-   ##
==========================================
- Coverage   82.12%   82.07%   -0.05%     
==========================================
  Files         183      183              
  Lines       48111    48108       -3     
  Branches     8667     8665       -2     
==========================================
- Hits        39510    39485      -25     
- Misses       6435     6452      +17     
- Partials     2166     2171       +5     

Files with missing lines	Coverage Δ
pytensor/gradient.py	77.62% <100.00%> (+0.05%)	⬆️
pytensor/link/jax/dispatch/tensor_basic.py	98.21% <100.00%> (ø)
pytensor/scan/basic.py	84.56% <100.00%> (ø)
pytensor/sparse/basic.py	82.57% <100.00%> (+0.02%)	⬆️
pytensor/tensor/conv/abstract_conv.py	76.05% <100.00%> (ø)
pytensor/tensor/extra_ops.py	88.01% <100.00%> (ø)
pytensor/tensor/rewriting/basic.py	94.24% <100.00%> (+0.09%)	⬆️
pytensor/tensor/rewriting/elemwise.py	91.13% <100.00%> (-0.02%)	⬇️
pytensor/tensor/rewriting/shape.py	82.02% <100.00%> (ø)
pytensor/tensor/subtensor.py	89.54% <100.00%> (ø)
... and 6 more

[ricardoV94]

@Armavica I removed the negative constant rewrite in the last commit