fallocate error in docker on Windows

[jeffbrl]

I am encountering an error with fallocate on Windows 11 and Docker Desktop using the WSL2 backend.

powershell> docker run -v .:/data -it --rm jeffbrl/ogxbox-image-builder /bin/bash
>>> from pyfatx import Fatx
>>> Fatx.create('/data/foo',8 * 1024 * 1024 * 1024)
fallocate: fallocate failed: Operation not supported
>>>

If I run the same commands from WSL2, I do not encounter the error.

I noticed that pyfatx uses different allocation behavior based on platform.

fatx/pyfatx/pyfatx/__init__.py

Line 286 in a1f4ede

subprocess.run(['fallocate', '-l', str(size), path])

Is a change needed here to accommodate WSL2? If this change isn't too complex, I can submit the PR.