Build fails with an internal build system error instead of a validation error when threadsSupport is combined with Wasm64

How to reproduce:

1. Extract the attached “IN-151229“ project
2. Open a Terminal in the project’s directory
3. Run the following command: & "<Path to Editor.exe>" -batchmode -projectPath "<project directory>" -buildTarget WebGL -executeMethod Repro.Run -logFile "<project directory>/repro.log"
4. Wait for the building process to end
5. Open and observe the contents of repro.log

Actual result: An Internal build system error is thrown during the build
Expected result: "Multithreaded Wasm64 is not currently available" validation error is thrown before the build starts

Reproducible with: 6000.6.0b1, 6000.6.0f1, 6000.7.0a6
Could not test with: 6000.0.0f1, 6000.0.83f1, 6000.3.23f1, 6000.5.11f1, 6000.6.0a7 (Wasm64 is not available before 6000.6.0b1)

Reproducible on: Windows 11
Not reproducible on: No other environments tested