Refactor doctor.py into a directory (#13298)

lib/python/qmk/cli/doctor/macos.py

@@ -0,0 +1,13 @@
+import platform
+
+from milc import cli
+
+from .check import CheckStatus
+
+
+def os_test_macos():
+    """Run the Mac specific tests.
+    """
+    cli.log.info("Detected {fg_cyan}macOS %s{fg_reset}.", platform.mac_ver()[0])
+
+    return CheckStatus.OK