Update all links in installation guide

[akshaysharmajs]

Some of the links like cryptography installation in file install.rst are outdated and require an update.
It will be nice to check for other parts of the documentation for the same issue.

[mehrdadep]

scarpy only have pages in community-staging and community on archlinux, so this is also invalid .. _AUR Scrapy package: https://aur.archlinux.org/packages/scrapy/

[joesinghh]

Can i get assigned to This issue @Gallaecio

[Gallaecio]

There’s already #4899