Prepare 0.4.0 release

[nikola-jokic]

Notable changes (Excluding tests):

• Surface EphemeralRunnerSet stats to AutoscalingRunnerSet #2382
• Remove list/watch secrets permission from the manager cluster role. #2276
• Delay role/rolebinding creation to gha-runner-scale-set installation time #2363
• Support the controller to watching a single namespace. #2374
• Add labels to autoscaling runner set subresources to allow easier inspection #2391
• Fix bug preventing env variables from being specified #2450
• Enhance quickstart guide with less noise and more troubleshooting guidelines #2435
• Ignore extra dind container when contaerinMode.type=dind. #2418
• Fix helm uninstall cleanup by adding finalizers and cleaning them from the controller #2433
• Add ImagePullPolicy to the AutoscalingListener, configurable through Manager env #2477
• Treat .ghe.com domain as hosted environment #2480

[Link-]

TODO

• After merge, create and push tag: gha-runner-scale-set-0.4.0
• Verify new chart has been pushed to: https://github.com/actions/actions-runner-controller/pkgs/container/actions-runner-controller-charts%2Fgha-runner-scale-set-controller
• Verify new chart has been pushed to: https://github.com/actions/actions-runner-controller/pkgs/container/actions-runner-controller-charts%2Fgha-runner-scale-set
• Verify new image has been pushed to: https://github.com/actions/actions-runner-controller/pkgs/container/gha-runner-scale-set-controller