Remove usage of deprecated Assert::assertContainsOnly()

Author: GromNaN

tests/Tests/Functional/CustomTypeTest.php

@@ -47,7 +47,7 @@ public function testCustomTypeValueConversions(): void
 
         $country = $this->dm->find(Country::class, $country->id);
 
-        self::assertContainsOnly('DateTime', $country->nationalHolidays);
+        self::assertContainsOnlyInstancesOf('DateTime', $country->nationalHolidays);
     }
 
     public function testConvertToDatabaseValueExpectsArray(): void

tests/Tests/Query/FilterCollectionTest.php

@@ -22,7 +22,7 @@ public function testEnable(): void
 
         $enabledFilters = $filterCollection->getEnabledFilters();
         self::assertCount(1, $enabledFilters);
-        self::assertContainsOnly(BsonFilter::class, $enabledFilters);
+        self::assertContainsOnlyInstancesOf(BsonFilter::class, $enabledFilters);
 
         $filterCollection->disable('testFilter');
         self::assertEmpty($filterCollection->getEnabledFilters());