Top-edge pointer events missed on non-first workspace (scale ≠ 1)

[skrmc]

When using a fractional output scale (scale ≠ 1), pointer events at the very top edge of the screen do not reach maximized windows unless the window is on workspace 1.

Steps to reproduce with Chrome (tab bar):

• Switch to workspace 2 (or any workspace other than 1).
• Open and maximize Chrome.
• Move the cursor to the top edge.

Pointer events does not reach the window:

[skrmc]

Opened #3299.