Remap {key Alt I} from `anim.delete_key_v3d` to `anim.delete_key`. This
makes it keyframe removal symmetrical with keyframe insertion ({key I}).
Both the default keymap {key Alt I} and the Industry Compatible keymap
{key Alt S} have been updated.
Reviewed By: sybren, #animation_rigging
Maniphest Tasks: T88068
Differential Revision: https://developer.blender.org/D11528