Do not pass time getter to Chainstate helpers

Summary:
This is a partial backport of core#25168
https://github.com/bitcoin/bitcoin/pull/25168/commits/fa4ee53dca5ccf1b87f019f372ffc10528add943

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D14596