Demonstrate commit drag scroll reset on re-entry

When dragging a commit with auto-scrolling so that the original commit
leaves the viewport, dragging back into the view makes the original
commit snap back into view. This is a regression that was introduced by
aebf495dce.

pkg/integration/tests/interactive_rebase/drag_to_reorder_with_autoscroll.go

@@ -25,6 +25,14 @@ var DragToReorderWithAutoscroll = NewIntegrationTest(NewIntegrationTestArgs{
 			MouseMoveToBottom(1).
 			// Verify that the view scrolls
 			OriginYAtLeast(3).
+			// Move the mouse back into the viewport
+			MouseMove(1, 1).
+			/* EXPECTED:
+			// This keeps the scroll as it was
+			OriginYAtLeast(3).
+			ACTUAL: */
+			// This snaps back to reveal the original commit
+			OriginY(0).
 			MouseRelease().
 			SelectedLines(
 				Contains("commit-40"),