Ensure runtime paths are correct

Summary: Be sure our run time paths are correct run time paths.

Test Plan:
https://github.com/sithlord48/atcore/releases/tag/continuous

AppImage and dmg should still see the plugins.

Reviewers: laysrodrigues, tcanabrava, patrickelectric, leandrosantiago

Reviewed By: tcanabrava, patrickelectric

Subscribers: Atelier: AtCore

Tags: Atelier: AtCore

Differential Revision: https://phabricator.kde.org/D14964