Renamed at aliases to pt

[shreyas3156]

What is this PR about?
Closes #6572.

1. Renamed aliases from at to pt in modules, tests, and docs.
2. Modified variable names from pt to pnt to avoid conflicts in tests/distributions/

• test_continuous.py
• test_multivariate.py
• test_transform.py
• util.py

Checklist

• Explain important implementation details 👆
• Make sure that the pre-commit linting/style checks pass.
• Link relevant issues (preferably in nice commit messages)
• Are the changes covered by tests and docstrings?
• Fill out the short summary sections 👇

[codecov]

Codecov Report

Merging #6577 (48cd01c) into main (4da5edf) will decrease coverage by 6.08%.
The diff coverage is 89.01%.

❗ Current head 48cd01c differs from pull request most recent head 66da2c5. Consider uploading reports for the commit 66da2c5 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6577      +/-   ##
==========================================
- Coverage   92.02%   85.94%   -6.08%     
==========================================
  Files          92       92              
  Lines       15561    15561              
==========================================
- Hits        14320    13374     -946     
- Misses       1241     2187     +946     

Impacted Files	Coverage Δ
pymc/logprob/joint_logprob.py	87.77% <ø> (-11.12%)	⬇️
pymc/distributions/truncated.py	34.50% <6.66%> (-64.79%)	⬇️
pymc/logprob/mixture.py	30.21% <10.00%> (-68.14%)	⬇️
pymc/func_utils.py	18.60% <25.00%> (-69.77%)	⬇️
pymc/logprob/scan.py	20.00% <25.00%> (-76.93%)	⬇️
pymc/math.py	52.65% <48.14%> (-17.40%)	⬇️
pymc/logprob/rewriting.py	83.33% <50.00%> (-13.73%)	⬇️
pymc/logprob/transforms.py	66.09% <55.35%> (-30.05%)	⬇️
pymc/logprob/censoring.py	62.88% <60.00%> (-36.09%)	⬇️
pymc/pytensorf.py	85.92% <72.22%> (-6.42%)	⬇️
... and 32 more

... and 9 files with indirect coverage changes

[ricardoV94]

Modified variable names from pt to pnt to avoid conflicts in tests/distributions/

Good catch. Mind renaming them to the explicit point?

[ricardoV94]

There's a conflict. Otherwise looks good!

[ricardoV94]

I rebased on main. Will merge if tests pass :)

[ricardoV94]

Thanks a lot @shreyas3156