[3.13] gh-137668: Document that ord() supports also bytes and bytearray (GH-137669) (GH-137704)

(cherry picked from commit 35759fe2fa)

Python/bltinmodule.c

@@ -1969,15 +1969,21 @@ builtin_oct(PyObject *module, PyObject *number)
 /*[clinic input]
 ord as builtin_ord
 
-    c: object
+    character as c: object
     /
 
-Return the Unicode code point for a one-character string.
+Return the ordinal value of a character.
+
+If the argument is a one-character string, return the Unicode code
+point of that character.
+
+If the argument is a bytes or bytearray object of length 1, return its
+single byte value.
 [clinic start generated code]*/
 
 static PyObject *
 builtin_ord(PyObject *module, PyObject *c)
-/*[clinic end generated code: output=4fa5e87a323bae71 input=3064e5d6203ad012]*/
+/*[clinic end generated code: output=4fa5e87a323bae71 input=98d38480432e1177]*/
 {
     long ord;
     Py_ssize_t size;