s/skip/skipif/

Author: ambv

src/c/test_c.py

@@ -3018,7 +3018,7 @@ def test_string_assignment_to_byte_array():
     except ImportError:
         pass   # win32
 
-@pytest.mark.skip(
+@pytest.mark.skipif(
     is_ios,
     reason="For an unknown reason fscanf() doesn't read anything on 3.14"
            " and crashes on 3.13 (that's why it's not an xfail)",