These have been marked deprecated in the comments for some time,
(since f340f773) but the warnings
were never enabled.

A warning suppression is enabled for Abseil code so that when we
declare types in our code, we don't get a warning.

PiperOrigin-RevId: 532891102
Change-Id: Ife0c5696a061ea44769e02869e4e3d1196e86f9d