When a plugin extension has a dependency on maven-aether-resolver, the components of this artifact are added into the plugin realm even though Maven Core already provides them. This is a regression introduced by the rename of this module to maven-resolver-provider in 3.5.0.
This rename has kept all the classes of maven-aether-resolver for compatibility, therefore the old artifact name also needs to be exported by Maven Core in extension.xml.
A visible side-effect of this is
MDEPLOY-221, where the two MetadataGeneratorFactory components of maven-aether-provider (which are SnapshotMetadataGeneratorFactory and VersionsMetadataGeneratorFactory) are present twice as Guice bindings, and wrong metadata information is deployed as a consequence. This is due to the Flex Mojos plugin extension which depends on maven-aether-resolver used in the build.