Move to vanilla firecracker UPF

[CuriousGeorgiy]

Describe the enhancement
Vanilla firecracker snapshots that will be introduced in #794 will lack UPF and thus moving to vanillla firecracker UPF will require a separate integration effort.

Support for UPF was introduced in firecracker v1.1.0¹ and in firecracker-microvm/firecracker-go-sdk@2e09014.

Footnotes

1. https://github.com/firecracker-microvm/firecracker/releases/tag/v1.1.0 ↩