The name "Property constraint" is less ambiguous than "quality constraint", and it is the one used in Wikidata (see Property constraints portal, Wikidata:WikiProject property constraints, Template:Property constraints, 2020 report on Property constraints, property constraint (Q21502402), property constraint (P2302), item of property constraint (P2305)). Constraints or rules to ensure data quality can exist in many ways and at many levels (the Wikibase data model, abuse filters, API limits, etc.).
However, for historical reasons, the MediaWiki extension WikibaseQualityConstraints, the Phabricator project Wikibase-Quality-Constraints, and other technical elements still use "quality constraints". It is suggested to consider changing those names to "Property constraints".