gh-141612: Tests: Add missing assertions to test_trampoline_works_with_forks

[pareshjoshij]

Closes #141612.

This PR makes the test_trampoline_works_with_forks test in Lib/test/test_perf_profiler.py more robust by adding missing assertions.

The original test only verified the presence of symbols in their respective perf maps (parent symbols in parent map, child symbols in child map). It did not verify the absence of those symbols in the other process's map.

This change adds six self.assertNotIn calls to complete the test logic. It now verifies:

• Parent-specific symbols (e.g., py::foo) are not in the child's perf map.
• Child-specific symbols (e.g., py::foo_fork) are not in the parent's perf map.

This closes the gap in the test logic and prevents potential false positives. The test_perf_profiler test suite passes successfully with these changes.

• Issue: Tests: test_trampoline_works_with_forks assertions are incomplete #141612

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[pareshjoshij]

Hi @picnixz Sir ! , could you please review this when you get a moment?
It’s a small test-only improvement adding missing assertNotIn checks.
If everything looks good, kindly approve/merge.
Thank you! 🙏

[efimov-mikhail]

@pareshjoshij You can see, what form of result I suspect:
https://github.com/efimov-mikhail/cpython/commits/fix-perf-test-assertions/

[pareshjoshij]

So sorry @efimov-mikhail sir about that! :(

I tried to apply the fix via the GitHub web UI because I am currently out of town and away from my development setup. Unfortunately, it looks like the web editor mishandled the indentation.

I will fix this properly as soon as I get back to my computer. That said, if you'd prefer not to wait, please feel free to commit the edit directly—I have 'Allow edits from maintainers' enabled.

[efimov-mikhail]

Don't worry, it's not a problem and there's no hurry.

[efimov-mikhail]

LGTM.

Could you please take a look, @picnixz ?