I note the MediaWiki Language Extension Bundle/translate support here might be a problem.
The replacement MatchQuery class is now in master, and backported to 1.35.... But it's not in 1.34 (of Elastica); but that is EOL for most purposes.
We could just backport rEELA290255cc67b0: Update ruflin/elastica to 6.1.1 and then rEELA65ac9f8baa7b: Updating ruflin/elastica (6.1.1 => 6.1.3) to 1.34 if it's needed..
Or if the next release of MLEB is going to require MW >= 1.35, we don't need to worry about this anyway