Clean up architecture diagram

Created by: nicksnyder

This change makes multiple improvements to the architecture diagram (can be reviewed commit by commit)

1. Regenerated the diagram (it was out of sync from the source)
2. Reverted most of https://github.com/sourcegraph/sourcegraph/pull/29893/ because that PR introduced duplicate nodes for worker, frontend and postgres that messed up the diagram. As far as I can tell, that PR only needed to add the new code insights DB (which I have left in the diagram). This diagram only needs to include actual deployable services, and since code insights is not a separate deployable, it doesn't need to be explicitly represented in this diagram (except for the DB).
3. Fixed warnings of labels getting clipped by increasing size of code host and client bubbles
4. Removed "internal services" grouping because it didn't seem to add any clarity to the diagram.
5. Add edge to indicate searcher depends on zoekt for structural search

Test plan

Visually inspected the new architecture diagram.