Rollup merge of rust-lang#98191 - TaKO8Ki:remove-rest-of-unnecessary-…

…to-string, r=Dylan-DPC

Remove the rest of unnecessary `to_string`

I removed most of unnecessary `to_string` in rust-lang#98043. This patch removes the rest of them I missed.

clippy_utils/src/sugg.rs

@@ -771,7 +771,7 @@ impl<T: LintContext> DiagnosticExt<T> for rustc_errors::Diagnostic {
             }
         }
 
-        self.span_suggestion(remove_span, msg, String::new(), applicability);
+        self.span_suggestion(remove_span, msg, "", applicability);
     }
 }