darwin: Fix single_module is obsolete warning

In XCode 15's linker, -single_module is the default and otherwise
passing it as a flag results in a warning being raised:

    ld: warning: -single_module is obsolete

This patch fixes this warning by, at configure time, determining whether
the linker supports -single_module (which is likely false for all
non-darwin linkers, and true for darwin linkers in previous versions of
macOS), and using that information at runtime to decide to pass or not
the flag in the invocation.

Fixes #24168