macOS py3.12 CI wheel validation frequently failing

[taalexander]

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Describe the bug

On #3868 @khalatepradnya has noted that the macOS py3.12 CI wheel validation job is frequently failing in remote platform tests with something like

FAILED build/validation/tests/remote/test_remote_platform.py::test_run_async - RuntimeError: Failed to launch kernel. Error: HTTP POST Error - status code 0: Received HTTP/0.9 when not allowed

See a CI run here

Steps to reproduce the bug

See a CI run here

Expected behavior

Passes CI

Is this a regression? If it is, put the last known working version (or commit) here.

Not a regression

Environment

• CUDA-Q version: main
• Python version: 3.12
• C++ compiler: Clang 17
• Operating system: macOS 26.2

Suggestions

No response

[taalexander]

Initially, I was thinking this might be a utilization issue with CI runners. I'm unable to reproduce this locally with concurrent stress testing alongside repeated test_remote_platform.py::test_run_async calls despite trying in a number of ways on Python 3.12, Tahoe 26.2. This is likely an issue with the CI runner specifically and possibly how runners are virtualized/shared. The test runs 10 concurrent calls to the server across HTTP and only some of these have an issue.