egui: fix scroll not sticking when scrollbar is hidden (#3434)

Before:


https://github.com/emilk/egui/assets/4723091/4b42842c-4f34-45d1-9538-29cd0bfd614e


https://github.com/emilk/egui/assets/4723091/7544e300-5b9a-4b2b-aaa4-9acade69fa75

After:


https://github.com/emilk/egui/assets/4723091/d720286f-a166-4891-874a-350b15683587

Author: LoganDark

crates/egui/src/containers/scroll_area.rs

@@ -812,6 +812,11 @@ impl Prepared {
 
         // Paint the bars:
         for d in 0..2 {
+            // maybe force increase in offset to keep scroll stuck to end position
+            if stick_to_end[d] && state.scroll_stuck_to_end[d] {
+                state.offset[d] = content_size[d] - inner_rect.size()[d];
+            }
+
             let show_factor = show_bars_factor[d];
             if show_factor == 0.0 {
                 state.scroll_bar_interaction[d] = false;
@@ -882,11 +887,6 @@ impl Prepared {
                 )
             };
 
-            // maybe force increase in offset to keep scroll stuck to end position
-            if stick_to_end[d] && state.scroll_stuck_to_end[d] {
-                state.offset[d] = content_size[d] - inner_rect.size()[d];
-            }
-
             let from_content = |content| remap_clamp(content, 0.0..=content_size[d], main_range);
 
             let handle_rect = if d == 0 {