[upload-charm] always uses the latest revision of the resource

[nsklikas]

Bug Description

The upload-charm action:

1. pushes a resource to charmhub (https://github.com/canonical/charming-actions/blob/main/src/services/charmcraft/charmcraft.ts#L54)
2. Pulls all the resource's revisions and uses the latest (https://github.com/canonical/charming-actions/blob/main/src/services/charmcraft/charmcraft.ts#L56)

Perhaps this was caused by a charmhub API change, but if you push a resource to charmhub that already exists, that resource does not get a new revision. This wasn't always the case.

This means that if a charm will always use the latest resource version and not the one defined in the metadata.

Instead uploadResource should run something like:
charmcraft upload-resource <charm-name> oci-image --image <sha> --format json --verbosity brief

And parse the output to get the revision, the call to list all the revisions is not needed.

To Reproduce

Downgrade the image in a charm's metadata

Environment

github?

Relevant log output

https://github.com/canonical/kratos-operator/actions/runs/8919940662/job/24497519038 (the resource uploaded with the charm is a difference version from the one defined in the metadata)

Additional context

No response