gh-150948: Exclude macOS semaphore header from c-analyzer

[zainnadeem786]

Summary

Exclude Modules/_multiprocessing/semaphore_macosx.h from the c-analyzer parser configuration.

Issue

check-c-globals.py scans files matched by Modules/**/*.h. The macOS-specific header Modules/_multiprocessing/semaphore_macosx.h includes:

#include <sys/sysctl.h>

This header is not available on non-macOS CI environments, causing preprocessing to fail before the analyzer can inspect the file.

As a result, the "Check for unsupported C global variables" job can fail due to a platform-specific dependency rather than an actual c-analyzer issue.

Fix

Add Modules/_multiprocessing/semaphore_macosx.h to the EXCLUDED list in Tools/c-analyzer/cpython/_parser.py.

This follows the existing pattern used for other platform-specific files that cannot be parsed reliably across all CI platforms, such as:

• Modules/_scproxy.c
• Modules/_winapi.c
• platform-specific dynload implementations

Rationale

The current c-analyzer workflow already relies on explicit exclusions for files that depend on OS-specific headers unavailable on other platforms.

Since semaphore_macosx.h depends on the macOS-only sys/sysctl.h header, excluding it is consistent with the existing policy and avoids unrelated CI failures.

Fixes gh-150948.

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[StanFromIreland]

I'm sorry but I'm closing. This file does not exist, it is being considered as part of #130913. If we decide to merge that PR, we can add the exclusion there, too.