feat: added workflow for closing old PRs

[Asymtode712]

Related Issue

Closes #343

Description

This feature aims to automate the management of open PRs in a repository, ensuring that outdated or abandoned PRs are closed in a timely manner. By doing so, it helps maintain repository hygiene, improves workflow efficiency, and provides a better experience for both maintainers and contributors.

Checklist

• [X] My code adheres to the established style guidelines of the project.
• [X] I have included comments in areas that may be difficult to understand.
• [X] My changes have not introduced any new warnings.
• [X] I have conducted a self-review of my code.