ENH Float fmt in print_trainable_parameters (#1648)

This PR replaces `trainable%: 0.5916145025956931` with `trainable%:
0.5916` as it's done already in `src/peft/mixed_model.py`.

src/peft/peft_model.py

@@ -570,7 +570,7 @@ def print_trainable_parameters(self) -> None:
         trainable_params, all_param = self.get_nb_trainable_parameters()
 
         print(
-            f"trainable params: {trainable_params:,d} || all params: {all_param:,d} || trainable%: {100 * trainable_params / all_param}"
+            f"trainable params: {trainable_params:,d} || all params: {all_param:,d} || trainable%: {100 * trainable_params / all_param:.4f}"
         )
 
     def __getattr__(self, name: str):