Pickling of `ParamSpecArgs` and `ParamSpecKwargs` is not covered

[sobolevn]

I also tried to remove these lines and executed (just to be sure):

./python.exe -m test test_typing test_types test_annotationlib test_type_annotations test_type_aliases test_type_params test_copyreg test_pickle

And all tests still pass.
So, I added a simple test for that.

Linked PRs

• gh-128615: Cover pickling of ParamSpecArgs and ParamSpecKwargs #128616
• [3.13] gh-128615: Cover pickling of ParamSpecArgs and ParamSpecKwargs (GH-128616) #128625
• [3.12] gh-128615: Cover pickling of ParamSpecArgs and ParamSpecKwargs (GH-128616) #128626