Issue #22413: Remove comment made out of date by Argument Clinic
diff --git a/Modules/_io/stringio.c b/Modules/_io/stringio.c
index 21c2b19..73018a5 100644
--- a/Modules/_io/stringio.c
+++ b/Modules/_io/stringio.c
@@ -696,10 +696,8 @@
     char *newline = "\n";
     Py_ssize_t value_len;
 
-    /* Parse the newline argument. This used to be done with the 'z'
-       specifier, however this allowed any object with the buffer interface to
-       be converted. Thus we have to parse it manually since we only want to
-       allow unicode objects or None. */
+    /* Parse the newline argument. We only want to allow unicode objects or
+       None. */
     if (newline_obj == Py_None) {
         newline = NULL;
     }