modelCheckpoints fail on colab with keras format

[KenoLeon]

Like title says, also see here :

https://stackoverflow.com/questions/76701617/the-following-arguments-are-not-supported-with-the-native-keras-format-opti/77342304#77342304

They work when I change the format to .tf and add save_format="tf" ...

callbacks = [ keras.callbacks.ModelCheckpoint("jena_lstm.tf", save_best_only=True, save_format="tf") ]