Fix xsd NS

[pzygielo]

$ wget https://codehaus-plexus.github.io/modello/xsd/modello-1.4.0.xsd
$ 
$ git checkout 48094bdb
$ xmlstarlet val -s modello-1.4.0.xsd -e maven-release-manager/src/main/mdo/release-descriptor.mdo
maven-release-manager/src/main/mdo/release-descriptor.mdo:22.140: Element '{https://codehaus-plexus.github.io/MODELLO/1.4.0}model': No matching global declaration available for the validation root.
maven-release-manager/src/main/mdo/release-descriptor.mdo - invalid
$ 
$ git checkout 0f4a5a8c
$ xmlstarlet val -s modello-1.4.0.xsd -e maven-release-manager/src/main/mdo/release-descriptor.mdo
maven-release-manager/src/main/mdo/release-descriptor.mdo - valid

[pzygielo]

workflow job macos/jdk17 doesn't look good - 20m and no output from maven.

Seems it's able to complete after all - for example https://github.com/apache/maven-release/runs/5172595213?check_suite_focus=true#step:7:3837 took +2h 😄