Remove more references to 'model' in GPUI APIs (#23693)

Release Notes:

- N/A

crates/vim/src/normal/repeat.rs

@@ -130,7 +130,7 @@ impl Replayer {
                 text,
                 utf16_range_to_replace,
             } => {
-                let Some(Some(workspace)) = window.root_model::<Workspace>() else {
+                let Some(Some(workspace)) = window.root::<Workspace>() else {
                     return;
                 };
                 let Some(editor) = workspace

crates/vim/src/normal/search.rs

@@ -291,7 +291,7 @@ impl Vim {
         };
         let count = Vim::take_count(cx).unwrap_or(1);
         let prior_selections = self.editor_selections(window, cx);
-        let vim = cx.model().clone();
+        let vim = cx.entity().clone();
 
         let searched = pane.update(cx, |pane, cx| {
             self.search.direction = direction;
@@ -425,7 +425,7 @@ impl Vim {
                 result.notify_err(workspace, cx);
             })
         }
-        let vim = cx.model().clone();
+        let vim = cx.entity().clone();
         pane.update(cx, |pane, cx| {
             let Some(search_bar) = pane.toolbar().read(cx).item_of_type::<BufferSearchBar>() else {
                 return;