Fix std::filesystem::remove on ReFS targets

[BillyONeal]

Fix std::filesystem::remove on ReFS targets by falling back to standard delete on ERROR_NOT_SUPPORTED.

Resolves DevCom-857535.

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[BillyONeal]

I manually tested this on a Windows Server machine with an ReFS volume but we have no good means of automating such a test as our tests need to work on machines without such volumes available. I tried to run our P0218R1_filesystem\test.cpp test targeting ReFS to see if there were other bits that needed to shake out; sadly that test doesn't work on ReFS because ReFS does not support hard links.