Fix display profile update when moving across screens

This fix an issue where the display profile is sometimes not updated when the window is dragged across screens. (I had only tried reproducing this on Windows.)

Test Plan

1. In Krita, set different display profile for the two monitors. (scRGB is a good one as it makes the canvas dark which is easy to spot.)
2. Open a document.
3. Drag the window across monitors repeatedly to verify that it always updates the correct display profile.

Due to the issue being intermittent, this cannot really guarantee that the issue is fixed.

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
• I made sure my commits build individually and have good descriptions as per KDE guidelines.
• I made sure my code conforms to the standards set in the HACKING file.
• I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.