Fix for deprecated dynamic property

[BenjaminHoegh]

This pull request introduces a new property to the ParsedownExtended class to store a list of internal hosts loaded from configuration.

Changes to ParsedownExtended class:

• src/ParsedownExtended.php: Added a new private property $internalHosts to store a list of internal hosts loaded from configuration. This complements the existing $internalHostsSet property for link processing.

[Copilot]

Pull Request Overview

This PR adds a new private property to ParsedownExtended for storing a list of internal hosts from configuration.

• Introduces $internalHosts property with default empty array
• Adds PHPDoc for the new property

Comments suppressed due to low confidence (2)

src/ParsedownExtended.php:60

• Consider specifying the element type in the PHPDoc (e.g., @var string[]) for better clarity and static analysis support.

    /** @var array $internalHosts List of internal hosts loaded from configuration */

src/ParsedownExtended.php:61

• [nitpick] Add a unit test to verify that $internalHosts is correctly populated from configuration and integrated into link processing behavior.

    private array $internalHosts = [];