Fix scroll jitter by ignoring autoscroll events if following
Thorsten Ball
,
Antonio
, and
Julia
created
When following someone else we saw jitter because
`ScrollPositionChanged` events were battling `SelectionsChanged` events,
both of which were scrolling the viewport.
This ignores the ScrollPositionChanged if autoscrolling is on.
Co-authored-by: Antonio <antonio@zed.dev>
Co-authored-by: Julia <julia@zed.dev>