Support EC2 IMDS v2

[iliana]

https://aws.amazon.com/blogs/security/defense-in-depth-open-firewalls-reverse-proxies-ssrf-vulnerabilities-ec2-instance-metadata-service/

• moondog - api: make pluto and moondog IMDSv2 compliant #705
• sundog - api: make pluto and moondog IMDSv2 compliant #705
• host-ctr - host-ctr: bumps aws-sdk-go and amazon-ecr-containerd-resolver version #707
• thar-admin - thar-admin: retrieve SSH public keys via IMDSv2 #706
• thar-control (currently packaged SSM agent does not support IMDSv2) - thar-control: pin amazon-ssm-agent to a version that supports imdsv2 #709
• migration for default admin and control container versions. migrations: host-containers default version migration redux and new common migration 'ReplaceTemplateMigration' #717
• aws-iam-authenticator version bump from 0.4.0 to 0.5.0 - aws-iam-authenticator: bump from v0.4.0 to v0.5.0 #699
• kubernetes
  • need to bump aws-sdk-go version in kubernetes dependencies
  • cni plugin image needs to be updated to support imdsv2

[iliana]

@etungsten has verified that this works if we backport the aws-sdk-go dependency in kubelet and the CNI plugin image. Tracking those backports in #784.