gh-114150: Clarify that ctypes.PYFUNCTYPE can release the GIL during the call (GH-114151)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

Author: arrmansa

Doc/library/ctypes.rst

@@ -2052,7 +2052,11 @@ See :ref:`ctypes-callback-functions` for examples.
 .. function:: PYFUNCTYPE(restype, *argtypes)
 
    The returned function prototype creates functions that use the Python calling
-   convention.  The function will *not* release the GIL during the call.
+   convention.  Unlike :func:`CFUNCTYPE` and :func:`WINFUNCTYPE`, ctypes does
+   *not* release the GIL before calling the foreign function, so the function
+   may safely use the Python C API. Note that this does not prevent the GIL
+   from being released *during* the call.
+
 
 Function prototypes created by these factory functions can be instantiated in
 different ways, depending on the type and number of the parameters in the call: