chore: Fix refining_impl_trait lint occurences (#11979)

These show up when compiling Zed with latest nightly, which means that
we'd have to do it one or two Rust releases down the line.
Release Notes:

- N/A

crates/diagnostics/src/diagnostics.rs

@@ -87,7 +87,7 @@ struct DiagnosticGroupState {
 impl EventEmitter<EditorEvent> for ProjectDiagnosticsEditor {}
 
 impl Render for ProjectDiagnosticsEditor {
-    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl Element {
+    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
         let child = if self.path_states.is_empty() {
             div()
                 .bg(cx.theme().colors().editor_background)