fix(store): update action handler type to allow Observable<unknown> and Promise<unknown> (#2385)

* test: integrations ng9 ivy

pin jest and jest-preset-angular versions

* fix(store): update action handler type to use Observable<unknown> and Promise<unknown>

Author: joaqcid

packages/store/src/actions/action-director.ts

@@ -21,7 +21,7 @@ export class ActionDirector {
     handlerFn: (
       ctx: StateContext<TStateModel>,
       action: InstanceType<TActionType>
-    ) => void | Observable<void> | Promise<void>,
+    ) => void | Observable<unknown> | Promise<unknown>,
     options: ɵActionOptions = {}
   ) {
     const actionHandler = this._actionHandlerFactory.createActionHandler(