Filtering MonoComponents when building remotely doesn't work

[rolfbjarne]

This code:

https://github.com/xamarin/xamarin-macios/blob/cfcfd42947c3b5d06b1351372c237e39a8b0f3e6/dotnet/targets/Xamarin.Shared.Sdk.targets#L459-L460

doesn't work when building remotely.

Example binlog output (binlog from #21142 (comment)):

vs a build on macOS (locally by me):

My initial unverified guess is because of the differences in the directory separator, but this needs verifying (preferably by a test).

Note that this doesn't seem to cause any problems, unless the customer explicitly asks us to pass -all_load to the native linker, in which the linker fails complaining about duplicate symbols.