gh-106948: Docs: Disable links for C standard library functions, OS utility functions and system calls

[erlend-aasland]

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📚 Documentation preview 📚: https://cpython-previews--107062.org.readthedocs.build/

[serhiy-storchaka]

malloc, realloc and free are referred in many different files. Maybe add them in nitpick_ignore? And calloc for complete.

[erlend-aasland]

malloc, realloc and free are referred in many different files. Maybe add them in nitpick_ignore? And calloc for complete.

Yes, I noticed. I'll add them, and I'll remove the _weakref since it does not belong to this PR really.

[serhiy-storchaka]

The most referred functions:

 3 :c:func:`!addstr` 3 :c:func:`calloc` 3 :c:func:`exec` 3 :c:func:`function__entry` 3 :c:func:`printf` 3 :c:func:`sigaction` 3 :c:func:`signal` 3 :c:func:`sprintf` 3 :c:func:`strerror` 4 :c:func:`devpoll` 4 :c:func:`lockf` 4 :c:func:`main` 4 :c:func:`snprintf` 4 :c:func:`stat` 4 :c:func:`system` 4 :c:func:`vsnprintf` 5 :c:func:`dlopen` 5 :c:func:`fcntl` 5 :c:func:`flock` 5 :c:func:`!getopt` 5 :c:func:`!scanf` 6 :c:func:`realloc` 8 :c:func:`select` 9 :c:func:`poll` 11 :c:func:`gmtime` 11 :c:func:`localtime` 18 :c:func:`fork` 21 :c:func:`free` 34 :c:func:`malloc` 

Some of them, like getopt are only referred in one file.

[serhiy-storchaka]

1. I am not sure that all functions referred at least 3 times should be added in nitpick_ignore. Many of them are only referred in one file (excluding NEWS entries). Memory management functions malloc, realloc and free are obvious candidates for inclusion. calloc can also be included besides it is only referred 3 times. gmtime and localtime are referred several times in two related modules, they also can be included. fork is referred in multiple files. poll is only referred in select.rst, but multiple times, it is questionable. Etc, etc. On other side, addstr is only mentioned in curses.rst, and in all three cases already with !. To me, it is an obvious candidate for not inclusion. function__entry is a strange thing, is it even a standard name?

2. I did not differentiate between C, Posix and Windows types, Posix and Windows environment variables. It is tiresome to find where exactly the name is defined (and some are defined on multiple platforms), and it does not really matter. I only grouped by the role.

It is my thoughts. If you disagree, go ahead, but may be some of them can be useful to you.

[erlend-aasland]

Thanks for your input. I think it makes sense to remove functions which are only mentioned a few times, and instead use ! to mark them up. I'll return to this later today.

[erlend-aasland]

Thanks for the review and insight, Serhiy. Highly appreciated!

[miss-islington]

Thanks @erlend-aasland for the PR 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[miss-islington]

Sorry, @erlend-aasland, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker b447e19e720e6781025432a40eb72b1cc93ac944 3.11

[bedevere-bot]

GH-107154 is a backport of this pull request to the 3.12 branch.

[bedevere-bot]

GH-107157 is a backport of this pull request to the 3.11 branch.