Consolidates discovery of Prefect server `Service`s to the base class #19666

Job	Run time
typesafety	2m 17s
docker, python:3.9	5m 27s
docker, python:3.10	5m 31s
Server Tests - python:3.9, postgres:14	6m 26s
docker, python:3.11	5m 4s
Server Tests - python:3.10, postgres:14	6m 18s
docker, python:3.12	5m 29s
Server Tests - python:3.11, postgres:14	5m 34s
Server Tests - python:3.12, postgres:14	6m 9s
Server Tests - python:3.9, sqlite	7m 7s
Server Tests - python:3.10, sqlite	6m 46s
Server Tests - python:3.11, sqlite	5m 53s
Server Tests - python:3.12, sqlite	6m 29s
Database and Orchestration Tests - python:3.9, postgres:14	7m 19s
Database and Orchestration Tests - python:3.10, postgres:14	7m 23s
Database and Orchestration Tests - python:3.11, postgres:14	6m 11s
Database and Orchestration Tests - python:3.12, postgres:14	7m 4s
Database and Orchestration Tests - python:3.9, sqlite	9m 14s
Database and Orchestration Tests - python:3.10, sqlite	9m 0s
Database and Orchestration Tests - python:3.11, sqlite	7m 58s
Database and Orchestration Tests - python:3.12, sqlite	8m 35s
Client Tests - python:3.9, postgres:14	10m 35s
Client Tests - python:3.10, postgres:14	10m 10s
Client Tests - python:3.11, postgres:14	9m 1s
Client Tests - python:3.12, postgres:14	9m 17s
Runner, Worker, Settings, Input, and CLI Tests - python:3.9, postgres:14	7m 0s
Runner, Worker, Settings, Input, and CLI Tests - python:3.10, postgres:14	7m 3s
Runner, Worker, Settings, Input, and CLI Tests - python:3.11, postgres:14	5m 52s
Runner, Worker, Settings, Input, and CLI Tests - python:3.12, postgres:14	6m 22s
	3h 22m 34s

Provide feedback