v0.6.0

This release contains bugfixes, new features, and minor public-facing
API changes, but no inter-component API changes.

Breaking API changes:

- NeonVM: Removed VirtualMachineSpec.ServiceAccountName (#140)
- NeonVM: Make vm-builder specific to Neon, with new vm-builder-generic
  for general-purpose use. vm-builder-generic is *almost* the same as
  the previous vm-builder, but it does not include vector by default (#133)
- Require label "autoscaling.neon.tech/enabled=true" for autoscaling to
  be enabled (#38)

Features:

- Allow annotation "autoscaling.neon.tech/bounds=..." to override
  scaling bounds (#128)
- NeonVM: add --quiet flag to vm-builder[-generic], which is off by
  default. Builds are more verbose without it. (#169)
- agent, plugin: Add prometheus metrics (#92, #174, #175)
- agent: Better config validation (#177)

Fixes:

- agent: always log informant register errors (#165)
- agent: fix runner log prefix (#159)
- NeonVM: fix ENTRYPOINT, CMD handling when there's mutiple strings (#184)

No protocol changes.

Upgrade path from v0.5.2:

- No ordering requirements.