pylint: Skip false-positive invalid-sequence-index

Pylint doesn't handle flow control and thus, doesn't understand
that a key of type `str` is not reachable at this point:

> ipalib/base.py:472: [E1126(invalid-sequence-index),
  NameSpace.__getitem__] Sequence index is not an int, slice, or instance
  with __index__)

Note: I faced this error on Python3.9 and didn't see it using
Python3.10.

Fixes: https://pagure.io/freeipa/issue/9117
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipalib/base.py

@@ -469,7 +469,7 @@ class NameSpace(ReadOnly):
         if isinstance(key, str):
             return self.__map[key]
         if type(key) in (int, slice):
-            return self.__members[key]
+            return self.__members[key]  # pylint: disable=invalid-sequence-index
         raise TypeError(
             TYPE_ERROR % ('key', (str, int, slice, 'object with __name__'),
                           key, type(key))