Revert "[clang][Docs] Added release note for D142609"

The associated commit was reverted and backported in a93ca35, so this
release note line should also be removed.

This reverts commit 061e855.

Author: hazohelet

clang/docs/ReleaseNotes.rst

@@ -477,9 +477,6 @@ Improvements to Clang's diagnostics
 - ``-Wformat`` will no longer suggest a no-op fix-it for fixing scoped enum format
   warnings. Instead, it will suggest casting the enum object to the type specified
   in the format string.
-- Clang now emits ``-Wconstant-logical-operand`` warning even when constant logical
-  operand is on left side.
-  (`#37919 <https://github.com/llvm/llvm-project/issues/37919>`_)
 - Clang contexpr evaluator now displays notes as well as an error when a constructor
   of a base class is not called in the constructor of its derived class.