how can I permanently remove safari from IPad 5th generation

You can delete some of the built-in apps but not Safari

It's not listed here:

Delete built-in Apple apps from the Home Screen on your iOS 14 or later or iPadOS device or Apple Watch - Apple Support

You can’t remove it. You can disable it using restrictions… why would you even want to do this?

You cannot delete it if you wish (it is not a deletable iOS App). You can remove it from the Home Screen, but it will still be in App Library.