Lucio Wallriding Aim Practice
You can add any kind of bot you want; they won't be able to attack you.
The damage while on the ground is minimized if you're bhopping. I didn't want to completely prevent you from practicing diving and killing enemies, but you'll have to do it quick. You can swap to heal aura to heal up which is good practice.
Supported maps are Lijiang Gardens (obviously), Ilios Ruins (the pillars are fun) and Nepal Sanctum (for long range practice). You can add your own if you want.