Fix clippy::needless_borrow lint violations (#36444)

Release Notes:

- N/A

crates/gpui/src/platform.rs

@@ -1508,7 +1508,7 @@ impl ClipboardItem {
 
         for entry in self.entries.iter() {
             if let ClipboardEntry::String(ClipboardString { text, metadata: _ }) = entry {
-                answer.push_str(&text);
+                answer.push_str(text);
                 any_entries = true;
             }
         }