For historical context, we attempted to upgrade maven before, just to hit a problem with maven/artefactory: Maven version will be upgraded in CI this weekend [25th April]
You should be now able to use newer versions of maven with our maven redirect. The following URLs should work with any modern maven:
https://mavenrepo.openmrs.org/snapshots
https://mavenrepo.openmrs.org/nexus/content/repositories/snapshots
At some point in the next weeks, I will upgrade maven in our bamboo agents.