Docs: Use more specific type in description for `_WP_Dependency::$deps`.

Props marekdedic.
See #48303.

git-svn-id: https://develop.svn.wordpress.org/trunk@47399 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-dependency.php

@@ -37,7 +37,7 @@ class _WP_Dependency {
 	 * An array of handle dependencies.
 	 *
 	 * @since 2.6.0
-	 * @var array
+	 * @var string[]
 	 */
 	public $deps = array();