Remove numpy dependencies in src/lightning/pytorch

[Peiffap]

What does this PR do?

Removes dependency on numpy in part of the codebase (src/lightning/pytorch), as mentioned in #17278.

Partially fixes #17278

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📚 Documentation preview 📚: https://pytorch-lightning--19841.org.readthedocs.build/en/19841/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 53%. Comparing base (fd86ea7) to head (737fda6).
Report is 106 commits behind head on master.

❗ There is a different number of reports uploaded between BASE (fd86ea7) and HEAD (737fda6). Click for more details.

HEAD has 407 uploads less than BASE

Flag	BASE (fd86ea7)	HEAD (737fda6)
python3.10	33	11
cpu	119	22
lightning	72	15
pytest	80	2
lightning_fabric	19	0
python3.11	40	5
gpu	4	2
python3.8	23	6
examples	9	0
app	9	0
tpu	2	0
pytorch2.0	23	12
pytest-full	45	22
pytorch_lightning	19	9
pytorch2.2	6	3
pytorch2.3	6	2
pytorch2.1	10	5
lightning_app	4	0

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #19841      +/-   ##
==========================================
- Coverage      84%      53%     -31%     
==========================================
  Files         426      418       -8     
  Lines       35256    35103     -153     
==========================================
- Hits        29679    18695   -10984     
- Misses       5577    16408   +10831     

[awaelchli]

Thanks a lot for your recent PRs @Peiffap!