pyoxidizer: use in-memory resources on non-Windows platforms In-memory resources were disabled for macOS in 7bc1beed, and for all platforms in c900d962. Unfortunately this made it so that we were no longer producing standalone binaries on these platforms, and would have to ship the .py and .pyc files alongside the pyoxidized binary. These changes are no longer necessary after f6b04591, which disabled pep517 and solved the issue we were encountering. Differential Revision: https://phab.mercurial-scm.org/D11734