Please update xamarin-macios to consume zlib-ng from dotnet/runtime

[carlossanlop]

The dotnet/runtime repo has migrated from consuming madler/zlib and zlib-intel to consuming zlib-ng. We merged this PR on 7/2 to achieve that: dotnet/runtime#101465

The main issue tracking this migration effort is dotnet/runtime#101465

In consequence, xamarin-macios and xamarin-android might need to make changes to ensure they retarget their dependencies appopriately.

Note: We ensured that mobile platforms find and consume the system-installed zlib, but are going to delete the zlib and zlib-intel references from the repo. So please help determine if you need to take actions on this repo.

This needs to be done before .NET 9 gets published.

Please let @carlossanlop or @akoeplinger know if you have any questions.

[rolfbjarne]

We don't consume zlib ourselves, we only link with it:

xamarin-macios/dotnet/targets/Xamarin.Shared.Sdk.targets

Lines 1524 to 1525 in 7e615b0

	<!-- Mono requires zlib, iconv, and the "Compression framework" -->
	<_MainLinkerFlags Include="-lz" />

so I don't think we'll have to do much, if anything, here.

Leaving open until we've gotten the change from .NET though.

[rolfbjarne]

Closing, everything seems to be working fine.