fix: enable parallel builds by suffixing binfmt registration

[mmalecki]

Previously we've registered a binfmt handler with a static name. When attempting to run > 1 build in parallel, that led to a race for the registration, with the loser of the race left with a failed build altogether.

Append a random suffix to our registration name to fix this behavior.

[solo-build-bot[bot]]

Waiting for approval from someone in the solo-io org to start testing.