docker images used in many tests are about to be removed

[pjfanning]

docker.io are already doing brown-outs and it's only a matter of time before they are removed.

This IronMQ failure is just one of many.

Example

Pulling ironauth (iron/auth:)...
latest: Pulling from iron/auth
[DEPRECATION NOTICE] Docker Image Format v1, and Docker Image manifest version 2, schema 1 support will be removed in an upcoming release. Suggest the author of docker.io/iron/auth:latest to upgrade the image to the OCI Format, or Docker Image manifest v2, schema 2. More information at https://docs.docker.com/go/deprecated-image-specs/
Digest: sha256:bb294b8[14](https://github.com/apache/incubator-pekko-connectors/actions/runs/6343629147/job/17231955796#step:5:15)186729757beb35a130e8cccce2a056ef227ae4f85[15](https://github.com/apache/incubator-pekko-connectors/actions/runs/6343629147/job/17231955796#step:5:16)7d26b8536208
Status: Downloaded newer image for iron/auth:latest
Pulling ironmq (iron/mq:)...
Get "https://registry-1.docker.io/v2/": EOF