Update Test pipeline code to support Azure Dynamic agents

[smlambert]

We had previously done a prototype to support Azure dynamic agents. Since there is now an updated Azure Jenkins plugin, and a desire to also have a set of different containers to run on (mimicking what is available via static docker containers currently, see https://github.com/adoptium/infrastructure/tree/master/ansible/playbooks/AdoptOpenJDK_Unix_Playbook/roles/DockerStatic/Dockerfiles).

These can be put into https://github.com/orgs/adoptium/packages/container/package/test-containers and referenced in test pipeline code. See #5683 for initial change.

Next steps can be to ensure we have a diversity of containers upon which to run tests on.

[sxa]

Commenting so I get updates ;-)