gh-122058: Lib/inspect: Update docstrings for isfunction, isgenerator, isframe, iscode. (#122059)

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Victor Stinner <vstinner@python.org>

Objects/frameobject.c

@@ -1721,7 +1721,7 @@ suspended:
 }
 
 PyDoc_STRVAR(clear__doc__,
-"F.clear(): clear most references held by the frame");
+"F.clear(): clear all references held by the frame");
 
 static PyObject *
 frame_sizeof(PyFrameObject *f, PyObject *Py_UNUSED(ignored))