[clang] Bugfix for chosing the correct deduction guide (PR #66487)

[Botond István Hprváth via cfe-commits]

HoBoIs wrote:

The paper where this came from is: https://wg21.link/P0620R0. most of this paper was already implemented.
Where is the paper tracking doc I need to update? https://clang.llvm.org/cxx_status.html claims this paper is implemented. 
Sorry if the following questions are trivial, I'm new to this.
In the release note should I put it under [Bug Fixes to C++ Support](https://github.com/llvm/llvm-project/blob/main/clang/docs/ReleaseNotes.rst#bug-fixes-to-c-support) or [Bug Fixes in This Version](https://github.com/llvm/llvm-project/blob/main/clang/docs/ReleaseNotes.rst#id88)? 

Where should I reference the standard in the PR? In the Description?

https://github.com/llvm/llvm-project/pull/66487