testSubprocessPlatformOptionsPreExecProcessActionAndProcessConfigurator consistently fails on macOS 26 and Swift 6.2.

To Reproduce
swift test --filter testSubprocessPlatformOptionsPreExecProcessActionAndProcessConfigurator

Expected behavior
Test passes

Actual behavior
Test fails with Caught error: Bad file descriptor
The culprit seems to be writeFD.duplicate(as: FileDescriptor(rawValue: 9000))

Environment (please complete the following information):

• macOS 26
• Apple Swift version 6.2 (swiftlang-6.2.0.16.14 clang-1700.3.16.4)