Remove reshape_t

[tjburch]

What is this PR about?

Addresses #6106, removing the reshape_t function and the lone reference to it.

I did run into local issues with tests in test_smc.py, but they're all NotImplementedErrors so it might be external?

Major / Breaking Changes

• None

Bugfixes / New features

• None

Docs / Maintenance

• Cleanup of reshape_t which is no longer necessary since reshape works in Aesara.

[canyon289]

Thanks for the contribution!

[codecov]

Codecov Report

Merging #6118 (52ad966) into main (761f77d) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #6118      +/-   ##
==========================================
+ Coverage   92.08%   92.12%   +0.04%     
==========================================
  Files          86       86              
  Lines       17861    17844      -17     
==========================================
- Hits        16447    16439       -8     
+ Misses       1414     1405       -9     

Impacted Files	Coverage Δ
pymc/distributions/mixture.py	95.40% <ø> (ø)
pymc/aesaraf.py	93.38% <100.00%> (+0.47%)	⬆️
pymc/gp/util.py	96.55% <100.00%> (ø)
pymc/model.py	88.23% <100.00%> (ø)
pymc/step_methods/metropolis.py	83.40% <100.00%> (ø)
pymc/tests/distributions/test_logprob.py	100.00% <100.00%> (ø)
pymc/variational/opvi.py	87.04% <100.00%> (ø)
pymc/parallel_sampling.py	86.79% <0.00%> (+0.99%)	⬆️
pymc/distributions/censored.py	100.00% <0.00%> (+7.50%)	⬆️