Use SmoothPixmapTransform when drawing cursor

This solves the pixelated look of the cursor under wayland, if the
scaling is set to a fractional value.

src/backends/drm/drm_output.cpp

@@ -157,6 +157,7 @@ bool DrmOutput::updateCursor()
     QPainter p;
     p.begin(c);
     p.setWorldTransform(logicalToNativeMatrix(cursor->rect(), 1, transform()).toTransform());
+    p.setRenderHint(QPainter::SmoothPixmapTransform);
     p.drawImage(QPoint(0, 0), cursorImage);
     p.end();
     return m_pipeline->setCursor(m_cursor->currentBuffer(), logicalToNativeMatrix(cursor->rect(), scale(), transform()).map(cursor->hotspot()));

src/effects/screenshot/screenshot.cpp

@@ -390,6 +390,7 @@ void ScreenShotEffect::grabPointerImage(QImage &snapshot, int xOffset, int yOffs
     }
 
     QPainter painter(&snapshot);
+    painter.setRenderHint(QPainter::SmoothPixmapTransform);
     painter.drawImage(effects->cursorPos() - cursor.hotSpot() - QPoint(xOffset, yOffset), cursor.image());
 }