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