validation: only call UpdatedBlockTip for active chainstate

Summary:
This notification isn't needed for background chainstates.

This is a partial backport of core#27596
https://github.com/bitcoin/bitcoin/pull/27596/commits/1e59acdf17309f567c370885f0cf02605e2baa58

Depends on D17888

Test Plan: tested on dev branch via the feature_assumeutxo functional test and a test on mainnet (including indexers)

Reviewers: #bitcoin_abc, roqqit

Reviewed By: #bitcoin_abc, roqqit

Differential Revision: https://reviews.bitcoinabc.org/D17889