Migrate container images from Google Container Registry to Artifact Registry

[ffjlabo]

Google Container Registry is deprecated and ended on 2025/03/18.

We need to migrate container images to Artifact Registry.

target images

• gcr.io/pipecd/helloworld
• gcr.io/pipecd/launcher
• gcr.io/pipecd/piped

[ffjlabo]

We finished the migration.

For the backward capability, we chose the way to host container images with the URL gcr.io on Artifact Registry.
https://cloud.google.com/artifact-registry/docs/transition/auto-migrate-gcr-ar