How to reproduce:
1. Create and open a new 2D project
2. Create a Tilemap GameObject in the Hierarchy
3. Open the Tile Palette
4. Create a new Tile Palette
5. Enable the "Select" tool and enable Grid
6. Right-click and drag the grid outside of the Grid view
7. Release the mouse outside of the Grid view
8. Move the mouse around inside the Grid view (without clicking)
9. Observe the Grid space in the Tile Palette

Actual result: Grid moves with mouse movement until the mouse is clicked
Expected result: Grid does not move on mouse movement

Reproducible in: 6000.0.2f1, 6000.0.63f1, 6000.2.14f1, 6000.3.0f1, 6000.4.0a5, 6000.5.0a2
Not reproducible in: 6000.0.1f1

Reproduced on: Windows 11 Pro (24H2)
Not reproduced on: No other environment tested

Note: Before regression, while holding the right mouse button or middle mouse button outside of the grid, it continues to pan. After regression, the panning abruptly stops while holding the mouse buttons