ci: Use official CouchDB docker image

[taratatach]

The official image on the Docker hub seems to be https://hub.docker.com/_/couchdb rather than https://hub.docker.com/r/apache/couchdb.

We try to use this image as the previous cannot be downloaded anymore by podman-machine which fails with this error:

Error: error pulling image "apache/couchdb:3.2.2": unable to pull apache/couchdb:3.2.2: 5 errors occurred:
    * Error initializing source docker://apache/couchdb:3.2.2: Error reading manifest 3.2.2 in docker.io/apache/couchdb: manifest unknown: OCI index found, but accept header does not support OCI indexes
    * Error initializing source docker://registry.fedoraproject.org/apache/couchdb:3.2.2: Error reading manifest 3.2.2 in registry.fedoraproject.org/apache/couchdb: manifest unknown: manifest unknown
    * Error initializing source docker://quay.io/apache/couchdb:3.2.2: Error reading manifest 3.2.2 in quay.io/apache/couchdb: unauthorized: access to the requested resource is not authorized
    * Error initializing source docker://registry.access.redhat.com/apache/couchdb:3.2.2: Error reading manifest 3.2.2 in registry.access.redhat.com/apache/couchdb: name unknown: Repo not found
    * Error initializing source docker://registry.centos.org/apache/couchdb:3.2.2: Error reading manifest 3.2.2 in registry.centos.org/apache/couchdb: manifest unknown: manifest unknown

Please make sure the following boxes are checked:

• [x] PR is not too big
• [x] it improves UX & DX in some way
• [ ] it includes unit tests matching the implementation changes
• [ ] it includes scenarios matching a new behaviour or has been manually tested
• [x] it includes relevant documentation