ci.jenkins.io: rollout of Maven 3.9.1

[Damien Duportal]

Hello dear contributors!

Ths email to let you know that today, the Jenkins infrastructure team deployed a new version of Maven to ci.jenkins.io agents (and on the whole infrastructure), instead of Maven 3.9.0.

If you see any issue, please comment in https://github.com/jenkins-infra/helpdesk/issues/3482.

Thanks!

Damien Duportal, for the Jenkins Infra team