Automated rollback of commit 63fb60bd85247f016fa1571b752f95445be9d56c.

*** Reason for rollback ***

This change was originally made to try to fix failing presubmits related to ImpossibleNullComparison. But this was instead fixed by cherry-picking https://github.com/bazelbuild/bazel/commit/83d0f2cafaac42e3b2b1822340f8f813ad4698e5 into the 6.3 branch. This change has been reverted to avoid disabling too many checks.

*** Original change description ***

Disable ImpossibleNullComparison

PiperOrigin-RevId: 532817246
Change-Id: I4165a5bc91dc0b12d1dd99d59526e344c32715e0