This Seeking Tech guide will explain how you can beat Miss Ruby without taking any damage in Sly Cooper and the Thievius Raccoonus (2024) on PS4 and PS5.
Use the following video as a reference:
For the first phase, carefully jump across the fangs until you get near her. Afterwards, double jump and then attack her. You should be able to avoid her tail attack with this combo.
When dodging the buttons, mash the button until you dodge it before moving on to the next button. If you keep mashing, you should be able to dodge her attacks without having to be in rhythm.
When you get close to her, make sure you double jump and then attack.
Continue doing these steps to end the fight without taking any damage.