Remove artifact `pkl-cli` from publishing

pkl-cli _is_ published to Maven Central, but depends on pkl-server which is not.
It should be published as well.

Start by tracing the publishing configuration for pkl-cli and its pkl-server dependency, then check how artifacts are published to Maven Central. Resolve the title/body conflict first: determine whether pkl-cli should be removed or pkl-server should be published as well; completion requires the agreed artifact relationship to work from Maven Central.

Written by the indexing model from the issue text.