fix intersection types in tests

Author: Tobion

Tests/Store/CombinedStoreTest.php

@@ -51,11 +51,11 @@ public function getStore(): PersistingStoreInterface
         return new CombinedStore([new RedisStore($redis)], new UnanimousStrategy());
     }
 
-    /** @var MockObject */
+    /** @var MockObject&StrategyInterface */
     private $strategy;
-    /** @var MockObject */
+    /** @var MockObject&BlockingStoreInterface */
     private $store1;
-    /** @var MockObject */
+    /** @var MockObject&BlockingStoreInterface */
     private $store2;
     /** @var CombinedStore */
     private $store;