Use awscli2 rather than awscli to deploy - less because I actually need
any specific functionality from the new version, and more because I
already use awscli2 on my systems and it's nice to always use the same
version of stuff
Change-Id: Id0e5b63dde1857c2e417ac2eeb2f769ebcc0f956
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3175
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI