Fix blurry icons by adding UseHighDpiPixmaps flag
Summary: When using fractional scaling, icons on the top and on both sides are blurred. This patch fixes the issue.
Test Plan:
No side effects.
Before:
After:
Reviewers: KDE Applications, yurchor
Reviewed By: yurchor
Subscribers: yurchor, kde-edu
Tags: KDE Edu
Differential Revision: https://phabricator.kde.org/D29450