Committing a block prior to indexing would leave the index database
in an inconsistent state until it is indexed, which could corrupt the
index in case of a unclean shutdown. Thus commit its predecessor.
Co-authored-by: Luke Dashjr <luke-jr+git@utopios.org>
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/25074 | core#25074]]