chore: add GitHub URL for PyPi

[andriyor]

Summary of Changes

Warehouse now uses the project_urls provided to display links in the sidebar on this screen, as well as including them in API responses to help the automation tool find the source code for Requests.

Docs: packaging.python.org/en/latest/guides/distributing-packages-using-setuptools/#project-urls

Related Issues

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[codecov[bot]]

Codecov Report

Merging #2033 (91f8ed8) into master (82ebcba) will not change coverage. The diff coverage is n/a.

@@            Coverage Diff            @@
##            master     #2033   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           63        63           
  Lines         6707      6707           
  Branches      1238      1238           
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  Hits          6707      6707           

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[CaselIT]

@CaselIT @kgriffs thoughts?

I think it would be an useful addition