Remove default values and psalm-pure annotation (by PHPStan)

Cleaned up code by removing the default value for `Named::$value` and `Inject::$optional`, ensuring they must be explicitly set upon instantiation. The `psalm-pure` annotation was also removed from the `getStringName` function, reflecting the function's possible side effects or method calls. These changes improve code clarity and enforce proper initialization practices.

Author: koriym

src/di/Bind.php

@@ -206,8 +206,6 @@ private function isRegistered(string $interface): bool
      * output: "varA=nameA,varB=nameB"
      *
      * @param array<string, string> $name
-     *
-     * @psalm-pure
      */
     private function getStringName(array $name): string
     {

src/di/Di/Inject.php

@@ -23,7 +23,7 @@ final class Inject implements InjectInterface
      *
      * @var bool
      */
-    public $optional = false;
+    public $optional;
 
     /**
      * @SuppressWarnings(PHPMD.BooleanArgumentFlag) // @phpstan-ignore-line

src/di/Di/Named.php

@@ -19,7 +19,7 @@
 final class Named
 {
     /** @var string */
-    public $value = '';
+    public $value;
 
     public function __construct(string $value)
     {