Reduce the access to med dispensers and lockers to only medstaff

[Mageziya]

From what I understand, the logic in giving janitors medical access is so that they specifically have access to medbay itself for cleaning. The ability for the janitor to practice medicine is a secondary, vaguely unintended feature made by how the access system works. If there was a way to just let them into medbay without granting them access to machines and lockers, it feels like that would be the ideal here.