i just made a decision and deleted windows partition but now i have windows 10 in grub menu although i updated grub my windows 10 and ubuntu both of them installed as EFI systems and i know both of them had a partition they used but i dont know how to delete windows boot files to delete windows completely from grub and my UEFI firmware
this the screenshot from gparted
as you see /dev/sda2 is efi partition what should i do?