gh-139231: Fix estimation of available stack size for recursion limit on macOS

[rokm]

On macOS, use pthread_get_stackaddr_np() and pthread_get_stacksize_np() to determine the stack address and size (used by code handling the recursion limit), rather than falling back to conservative hard-coded default of 4 MB.

Fixes#139231; the output of reproducer script is now:

Stack address: 6089916416 = 0x16AFCC000 Stack size: 16777216 = 16384.0 kB = 16.0 MB Stack pointer: 0x16AFCA140, depth: 7.69 kB Testing Recursion Limit Initial limit: 1000 Recursion level: 1, stack pointer: 0x16AFC9870, depth: 9.89 kB Recursion level: 2, stack pointer: 0x16AFC8FA0, depth: 12.09 kB ... Recursion level: 7586, stack pointer: 0x169FD0BA0, depth: 16365.09 kB Recursion level: 7587, stack pointer: 0x169FD0300, depth: 16367.25 kB Recursion Limit ok (reached level 7588) 

(i.e., stack is fully utilized, as expected).

• Issue: Under-estimated stack size for recursion limit (macOS + python >= 3.14) #139231

[python-cla-bot]

All commit authors signed the Contributor License Agreement.

[bedevere-app]

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

[miss-islington-app]

Thanks @rokm for the PR, and @markshannon for merging it 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-139290 is a backport of this pull request to the 3.14 branch.