Fix cmake build on macOS with Xcode generator

[asakovets]

1. Do not pass -mmacosx-version-min, use CMAKE_OSX_DEPLOYMENT_TARGET property instead. This fixes clang: error: overriding '-mmacosx-version-min=10.7' option with '-target arm64-apple-macos15.1' [-Werror,-Woverriding-t-option]

2. Do not throw error on -Wshorten-64-to-32 warning. At first I thought about fixing all occurrences of this warning, but it shortly became clear that there are just too many of them. I decided that it easier to leave it as a warning.

[zeux]

Wshorten-64-to-32

It's interesting that you had to disable it, as Makefile build doesn't need to.

[zeux]

Nor do I get either warning locally when building on macOS, using CMake 3.30 and Apple clang 16.0. But I'd definitely be happy to merge the deployment target change, just not sure about the other warning.

[zeux]

Ah, sorry, I missed the "Xcode generator" part. I do indeed have both issues in that generator; I guess it has a different set of warning defaults, so the truncation warning is explicitly enabled. Thanks!