gh-101100: Fix sphinx warnings in library/email.mime.rst

[sobolevn]

Before:

/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:35: WARNING: py:mod reference target not found: email.mime.base
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:65: WARNING: py:mod reference target not found: email.mime.nonmultipart
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:80: WARNING: py:mod reference target not found: email.mime.multipart
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:113: WARNING: py:mod reference target not found: email.mime.application
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:144: WARNING: py:mod reference target not found: email.mime.audio
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:178: WARNING: py:mod reference target not found: email.mime.image
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:212: WARNING: py:mod reference target not found: email.mime.message
/Users/sobolev/Desktop/cpython2/Doc/library/email.mime.rst:232: WARNING: py:mod reference target not found: email.mime.text

It renders the same way and has the same references.

• Issue: Fix all Sphinx reference warnings in the documentation #101100

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📚 Documentation preview 📚: https://cpython-previews--114635.org.readthedocs.build/

[serhiy-storchaka]

LGTM.

[miss-islington-app]

Thanks @sobolevn for the PR, and @serhiy-storchaka for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[bedevere-app]

GH-114640 is a backport of this pull request to the 3.12 branch.

[bedevere-app]

GH-114641 is a backport of this pull request to the 3.11 branch.