[3.14] gh-101100: Document os.uname_result and os.statvfs_result with related constants (GH-151301)

[miss-islington]

(cherry picked from commit 9688d25)

Co-authored-by: Cody Maloney cmaloney@users.noreply.github.com

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

[StanFromIreland]

@cmaloney, there are more undocumented (or incorrectly referenced) things on this branch, can you please push to this branch (as a triager, you should be able to) to either remove the files from .nitignore, or fix the issues? Thanks!

[vstinner]

Docs/Docs CI job failed with:

Error: must not contain warnings:

Doc/library/os.rst
  220: py:meth reference target not found: pop [ref.meth]
  220: py:meth reference target not found: clear [ref.meth]
  425: py:const reference target not found: MACOSX_DEPLOYMENT_TARGET [ref.const]
  2647: py:attr reference target not found: st_dev [ref.attr]
  2647: py:attr reference target not found: st_rdev [ref.attr]
  2653: py:attr reference target not found: st_dev [ref.attr]
  2653: py:attr reference target not found: st_rdev [ref.attr]
  3380: py:const reference target not found: S_IFCHR [ref.const]
  3380: py:const reference target not found: S_IFIFO [ref.const]
  3380: py:const reference target not found: S_IFBLK [ref.const]
  4427: py:const reference target not found: SIGABRT [ref.const]