Prepare the Si SR1 release

This means to:

• cherry-pick related bug corrections from master
• update project version in poms
• update dependencies if needed (mostly odlparent versions)
  https://docs.opendaylight.org/projects/integration-distribution/en/stable-silicon/platform-versions.html
• update others environment parameters e.g. for lighty.io and tox if needed (normally not)
• update release notes cf https://git.opendaylight.org/gerrit/c/docs/+/93588

Once that done, the release must be staged in Jenkins and then officially released using the self-service process

https://docs.opendaylight.org/en/stable-silicon/release-process/project-release.html

This last task can only be performed when all upstreams dep are ready i.e. when all managed projects have been released (prevision date ???).
The deadline is one week after all managed projects have been released.

Evaluation indicators:

• cherry-picks from master done
• magnesium stage release job OK in Jenkins
• tpce artifacts published on nexus