Attempt to fix: Sporadic Test Failure in thread.condition.condvarany/notify_one.pass.cpp

[Arup-Chauhan]

Hello, I am creating this draft PR to address the sporadic test failure in thread.condition.condvarany/notify_one.pass.cpp
within the LLVM libcxx test suite. The issue stems from timing assumptions that cause the test to fail intermittently in both internal and external CI environments.

I have previously worked in Microsoft STL's repository to unskip some of these sporadic tests.

Context:

The proposed fix adapts the approach used in the notify_all test (Issue #95944 and PR #97622 ) to enhance reliability by ensuring synchronization without relying on specific timing. This change should reduce or eliminate the occurrence of sporadic failures in this test.

I was not able to find any issue raised for notify_one.pass issue similar to notify_all.pass issue, should I raise one to bind with this PR as well?

I am seeking advice on this so adding a few people here
Please suggest @EugeneZelenko @lattner @topperc @shiltian @nikic @tbaederr please suggest.

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