updating the compSite.xml file to generate the Rodin 3.9 update site content
Upgrading the Rodin Core update site script
Increment version of plugins and features to 3.8
Increment version of parent in all pom.xml files to 3.8
Port to Eclipse 4.23 (2022-03)
Update copyright year in splash image
Update the year in all feature.properties files
Increment version of org.eventb.core to 3.6