[3.13] gh-120381: Fix inspect.ismethoddescriptor() (GH-120684)

[3.13] gh-120381: Fix inspect.ismethoddescriptor() (GH-120684)

The `inspect.ismethoddescriptor()` function did not check for the lack of
`__delete__()` and, consequently, erroneously returned True when applied
to *data* descriptors with only `__get__()` and `__delete__()` defined.

(cherry picked from commit dacc5ac71a8e546f9ef76805827cb50d4d40cabf)

Co-authored-by: Jan Kaliszewski <zuo@kaliszewski.net>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Alyssa Coghlan <ncoghlan@gmail.com>