servicecatalog: remove searcher dep on database (#64247)

Searcher doesn't speak to the database nor has it for a long time. See
https://github.com/sourcegraph/sourcegraph/pull/61463

Test Plan: The following command is empty

  go run ./dev/depgraph/ summary internal/database | grep 'cmd/searcher'

lib/servicecatalog/service-catalog.yaml

@@ -49,7 +49,6 @@ protected_services:
       - gitserver
       - migrator
       - repo-updater
-      - searcher
       - symbols
       - worker
       - precise-code-intel-worker