Fix pixmap scaling on HiDPI screens
Summary:
This fixes the pixelation seen when using display scaling on HiDPI screens. This fixes the main screen as well as the settings and other areas.
BUG: 390081
Before:
After:
Test Plan: Browse file structure in project, open settings and change values, ensuring functionality.
Reviewers: aacid, lesliezhai, rkflx
Reviewed By: rkflx
Subscribers: rkflx, ngraham
Differential Revision: https://phabricator.kde.org/D11669