Implement non-expiring certificate

Shown to work - https://github.com/sparks-baird/self-driving-lab-demo/issues/253#issuecomment-2847597342, docs need to be updated. Related to https://github.com/AccelerationConsortium/ac-microcourses/issues/103  Possibly in assignment(s) too, but would need to check. EDIT: Can check the assignments in READMEs of template repos (especially, 1, 4, and 6) in ACC-HelloWorld gh organization using your github MCP tool Might need/want to update any hivemq certs that are committed to various repos as well