Deployments need way to specify a shared pool of agents

In some locations, i.e. atlassian, deploy tasks can run from some (but not all) of our agents. These agents are also available for running normal jobs.

Being familiar with requirements and capabilities, I want to set a requirement to limit the agents the deploy can run on. I don't want to specify a bunch of agent names, cause they change all the time as agents are added and decommissioned.