test(hal): correct context array key type in normalizer test docblock (#7964)

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Tickets       | ∅
| License       | MIT
| Doc PR        | ∅

Author: soyuka

src/Hal/Tests/Serializer/ItemNormalizerTest.php

@@ -422,8 +422,8 @@ public function testMaxDepth(): void
     }
 
     /**
-     * @param array<int,mixed> $context
-     * @param array<int,mixed> $expected
+     * @param array<string,mixed> $context
+     * @param array<string,mixed> $expected
      */
     #[DataProvider('getSkipNullToOneRelationCases')]
     public function testSkipNullToOneRelation(array $context, array $expected): void