Fix imath reference in the isqrt() renaming section

Author: skirpichev

peps/pep-0791.rst

@@ -202,10 +202,11 @@ isqrt() renaming
 ---------------------------------------------
 
 There was a brief discussion about exposing :external+py3.14:func:`math.isqrt`
-as ``imath.sqrt`` in the same way that :external+py3.14:func:`cmath.sqrt` is
-the complex version of :external+py3.14:func:`math.sqrt`.  However, ``isqrt``
-is ultimately a different function: it is the floor of the square root.  It
-would be confusing to give it the same name (under a different module).
+as ``sqrt`` in the new namespace in the same way that
+:external+py3.14:func:`cmath.sqrt` is the complex version of
+:external+py3.14:func:`math.sqrt`.  However, ``isqrt`` is ultimately a
+different function: it is the floor of the square root.  It would be confusing
+to give it the same name (under a different submodule).
 
 
 Module name