python/pylint: Add exception for TypeVar names ('T')

'T' is a common TypeVar name, allow its use.

See also https://github.com/PyCQA/pylint/issues/3401 -- In the future,
we might be able to have a separate list of acceptable names for
TypeVars exclusively.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/setup.cfg

@@ -101,6 +101,7 @@ good-names=i,
            fh,  # fh = open(...)
            fd,  # fd = os.open(...)
            c,   # for c in string: ...
+           T,   # for TypeVars. See pylint#3401
 
 [pylint.similarities]
 # Ignore imports when computing similarities.