editor: Represent scroll offset with more precision (#39367)

Closes #5355

Release Notes:

- Fixed rendering glitches with files with more than 16 million lines
(that occured due to floating number rounding errors).

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

crates/workspace/src/workspace.rs

@@ -5989,7 +5989,7 @@ impl Workspace {
         self.left_dock.read_with(cx, |left_dock, cx| {
             let left_dock_size = left_dock
                 .active_panel_size(window, cx)
-                .unwrap_or(Pixels(0.0));
+                .unwrap_or(Pixels::ZERO);
             if left_dock_size + size > self.bounds.right() {
                 size = self.bounds.right() - left_dock_size
             }