[clang] [C++20][Modules] Prevent premature call to PassInterestingDeclsToConsumer() within FinishedDeserializing(). (PR #129982)

[Michael Park via cfe-commits]

mpark wrote:

> Thanks, the explanation and code change makes sense to me.

❤️

> Should this bugfix have a release note?

I've added a couple of bullet points in the release notes. Please let me know if this is along the lines of what's expected.

https://github.com/llvm/llvm-project/pull/129982