Fix workspace bottom obscured when bottom dock is full height (#27689)

When dragging the pane separator of the bottom dock to full window
height, the contents at the bottom of the dock and workspace window
overflowed the screen, becoming obscured. This happened because setting
a new size in resize_bottom_dock(...) was not taking in consideration
the top bounds of the workspace window, which caused the bottom bounds
of both dock and workspace to overflow. The issue was fixed by
subtracting the workspace.bounds.top() value to the dock's new size.

Closes #12966

Release Notes:

- N/A

crates/workspace/src/workspace.rs

@@ -5879,7 +5879,8 @@ fn resize_bottom_dock(
     window: &mut Window,
     cx: &mut App,
 ) {
-    let size = new_size.min(workspace.bounds.bottom() - RESIZE_HANDLE_SIZE);
+    let size =
+        new_size.min(workspace.bounds.bottom() - RESIZE_HANDLE_SIZE - workspace.bounds.top());
     workspace.bottom_dock.update(cx, |bottom_dock, cx| {
         bottom_dock.resize_active_panel(Some(size), window, cx);
     });