bpo-32593: Drop FreeBSD 9 and older support (#5232)

Drop support of FreeBSD 9 and older.
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 44b8d6a..6c50406 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -559,6 +559,7 @@
         self.assertRaises(TypeError, posix.minor)
         self.assertRaises((ValueError, OverflowError), posix.minor, -1)
 
+        # FIXME: reenable these tests on FreeBSD with the kernel fix
         if sys.platform.startswith('freebsd') and dev >= 0x1_0000_0000:
             self.skipTest("bpo-31044: on FreeBSD CURRENT, minor() truncates "
                           "64-bit dev to 32-bit")