gh-125893: Add type check for category argument in warnings.simplefilter and warnings.filterwarning

[hasrat17]

This PR addresses gh-125893 by adding a type check for the category argument in warnings.simplefilter and warnings.filterwarning,

Previously, warnings.filterwarnings correctly raised an error when the category argument was not a class, but warnings.simplefilter accepted invalid types without raising any error. This inconsistency could lead to confusion and improper warning filtering.

Both warnings.simplefilter and warnings.filterwarning were not raising any warnings while ran with python -O but now this is also handled.

$ ./amd64/python.exe -O -c "import warnings; warnings.resetwarnings(); warnings.simplefilter('default', category='Hello');  print(warnings.filters)"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\hasra\OneDrive\Documents\opensource\cpython\Lib\warnings.py", line 182, in simplefilter
    raise TypeError("category must be a Warning subclass, "
TypeError: category must be a Warning subclass, not 'str'

./amd64/python.exe -O -c "import warnings; warnings.resetwarnings(); warnings.filterwarnings('ignore', category=Warning); warnings.filterwarnings('ignore', category='Hello'); print(warnings.filters)"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\hasra\OneDrive\Documents\opensource\cpython\Lib\warnings.py", line 149, in filterwarnings
    raise TypeError("category must be a Warning subclass, "
TypeError: category must be a Warning subclass, not 'str'

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.