Fix the miscellaneous typo (GH-17700)

A character "i" is omitted.
(cherry picked from commit 527f9de)

Co-authored-by: cocoatomo <[email protected]>

Author: miss-islington

Doc/c-api/code.rst

@@ -42,7 +42,7 @@ bound into a function.
 
 .. c:function:: PyCodeObject* PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject *code, PyObject *consts, PyObject *names, PyObject *varnames, PyObject *freevars, PyObject *cellvars, PyObject *filename, PyObject *name, int firstlineno, PyObject *lnotab)
 
-   Similar to :c:func:`PyCode_New`, but with an extra "posonlyargcount" for positonal-only arguments.
+   Similar to :c:func:`PyCode_New`, but with an extra "posonlyargcount" for positional-only arguments.
 
    .. versionadded:: 3.8