Improve some PHPdocs based on existing Symfony stubs in PHPstan and Psalm

Author: mdeboer

SerializerInterface.php

@@ -19,14 +19,20 @@ interface SerializerInterface
     /**
      * Serializes data in the appropriate format.
      *
-     * @param mixed  $data    Any data
-     * @param string $format  Format name
-     * @param array  $context Options normalizers/encoders have access to
+     * @param array<string, mixed> $context Options normalizers/encoders have access to
      */
     public function serialize(mixed $data, string $format, array $context = []): string;
 
     /**
      * Deserializes data into the given type.
+     *
+     * @template TObject of object
+     * @template TType of string|class-string<TObject>
+     *
+     * @param TType                $type
+     * @param array<string, mixed> $context
+     *
+     * @psalm-return (TType is class-string<TObject> ? TObject : mixed)
      */
     public function deserialize(mixed $data, string $type, string $format, array $context = []): mixed;
 }