Avoid upgrading packages and try to update emulator

[adamnovak]

Changelog Entry

To be copied to the draft changelog by merger:

• vg CI builds of ARM containers should no longer segfault when upgrading libc

Description

We've been getting CI ARM Docker build crashes like this: https://ucsc-ci.com/vgteam/vg/-/jobs/109050#L2786

This should avoid docker/buildx#314 in two ways:

• We no longer upgrade packages from the base image when building the Docker image in CI. They should be up to date enough in the base image (but we might need to make sure that https://stackoverflow.com/q/77924205 is still true).
• We install a new binfmt-misc emulator that maybe won't have the crash bug. We're supposed to uninstall the old one and install the new one, but when we move the workload to shared machines we don't want the emulator getting uninstalled while in use.