9.2.2

The 9.2.2 is a patch release that addresses the issues below.

List of all changes

• Avoid throwing error if ClusterSource source is null (by @mike-000 in https://github.com/openlayers/openlayers/pull/15842)
• Fix feature type generics (by @ahocevar in https://github.com/openlayers/openlayers/pull/15843)