This edge release improves Linkerd's support for HttpRoute by allowing `parent_ref` ports to be optional, allowing HttpRoutes to be defined in a consumer's namespace, and adding support for the `ResponseHeaderModifier` filter. It also fixes a panic in the destination controller. * Added an option for disabling the network validator's security context for environments that provide their own * Added high-availability (HA) mode for the multicluster service-mirror * Added support for HttpRoute `parent_refs` that do not specify a port * Fixed a Grafana error caused by an incorrect datasource (thanks @albundy83!) * Added support for HttpRoutes defined in the consumer namespace * Improved the granularity of logging levels in the control plane * Fixed a race condition in the destination controller that could cause it to panic * Added support for the `ResponseHeaderModifier` HttpRoute filter * Updated extension CLI commands to prefer the `--register` flag over the `LINKERD_DOCKER_REGISTRY` environment variable, making the precedence more consistent (thanks @harsh020!)