Bump Envoy, remove support for unsupported versions

[sarahalsmiller]

Description

Bumping envoy versions to support 1.30 and 1.31, removing support for 1.26 and 1.27 https://www.envoyproxy.io/docs/envoy/latest/version_history/version_history

Testing & Reproduction steps

• CI should run and pass appropriately

Links

https://www.envoyproxy.io/docs/envoy/latest/version_history/version_history https://developer.hashicorp.com/consul/docs/connect/proxies/envoy

PR Checklist

• [ ] updated test coverage
• [ ] external facing docs updated
• [ ] appropriate backport labels added
• [ ] not a security concern