pref: disable the -macosx_version_min clang flag by default (#20297)

vlib/v/pref/pref.c.v

@@ -157,7 +157,7 @@ pub mut:
 	use_cache              bool   // when set, use cached modules to speed up subsequent compilations, at the cost of slower initial ones (while the modules are cached)
 	retry_compilation      bool = true // retry the compilation with another C compiler, if tcc fails.
 	use_os_system_to_run   bool   // when set, use os.system() to run the produced executable, instead of os.new_process; works around segfaults on macos, that may happen when xcode is updated
-	macosx_version_min     string = '10.7' // relevant only for macos and ios targets
+	macosx_version_min     string = '0' // relevant only for macos and ios targets
 	// TODO Convert this into a []string
 	cflags  string // Additional options which will be passed to the C compiler *before* other options.
 	ldflags string // Additional options which will be passed to the C compiler *after* everything else.