Deprecation Warning Thrown on PHP8.2

[jakewrfoster]

Issue

On PHP 8.2, the plugin throws the following deprecation warnings:

PHP Deprecated: Creation of dynamic property Media_Explorer::$file is deprecated in /my-cool-path/wp-content/plugins/media-explorer/class.plugin.php on line 27

PHP Deprecated:  Creation of dynamic property Media_Explorer::$plugin is deprecated in /my-cool-path/wp-content/plugins/media-explorer/class.plugin.php on line 89

Proposed solution

Add the props to the class so that they aren't dynamically created.

[jakewrfoster]

I am unable to push a branch to PR this, but some variation of the following could be added here to address the issue

/**
 * The plugin's file path.
 *
 * @var string
 */
public string $file;

[jakewrfoster]

and...

/**
 * The plugin's configuration.
 *
 * @var array
 */
public array $plugin;