Improve pickle hook

[byehack]

Can we add __future__ to base_library and remove doctest from pickle hook?

pyinstaller/PyInstaller/hooks/hook-pickle.py

Lines 15 to 16 in 70bb887

	# pickle also imports `doctest`, which also is only used when run an `__main__`. Anyway, excluding it made some Qt
	# related tests fail terribly with "ModuleNotFoundError: No module named '__future__'" when running the executable.

[rokm]

We can certainly try excluding doctest in the pickle hook.

As for __future__, we should check what is really going on - because this sounds like it should have been added as a hidden import somewhere else, instead of letting doctest (which probably directly imports __future__) be collected here...

[byehack]

script is simple while 1: exec(input('> '))
and compile command is

• left: python -m PyInstaller t.py
• right: python -m PyInstaller t.py --exclude-module doctest

the doctest brings unnecessary modules:

this picture is diff-files when doctest excluded.(files compared after extract of PYZ archives).
you can check them: z.zip

[rokm]

Done: #6798.