Fonts look less crisp on a setup with mixed scale factors

If all outputs have 100% scale factor, the fonts look crisp. If one of the outputs has a scale factor > 100%, the fonts won't look crisp anymore on outputs with 100% scale. See the attached screenshot. The top half shows text that's rendered on an output with 100% scale factor on a mixed scale factor setup, the bottom half shows text that's rendered on a setup where all outputs have 100% scale factor. Pay attention to letters such as "e"

The expected result is that text on outputs with 100% scale factor looks the same regardless of the scale factor of the other outputs.

The issue appeared after https://invent.kde.org/qt/qt/qtbase/-/commit/e7ddd490cf44ecd1c59b3798294ed2812fc5a940, which fixed another issue.

Downstream bug report: https://bugs.kde.org/show_bug.cgi?id=491015