TSC-120 Upgrade Oxygen to odlparent 3.1.1

As reported in RELENG-129, current Oxygen depends on both odlparent 3.1.0 and 3.1.1 (via yangtools), which causes issues when rebuilding the full projects (downstreams need to build both versions of odlparent).

We could simplify this by upgrading everyone to odlparent 3.1.1. https://logs.opendaylight.org/releng/vex-yul-odl-jenkins-1/integration-multipatch-test-oxygen/108 verifies that this doesn’t cause regressions (pre-CSIT).