Improve docker-related query test failure avoidance

tests/run-tests.sh

@@ -41,14 +41,6 @@ do
     # Specify the version we're testing against
     export PGTAG="${images["$version"]}"
 
-    # Start the db container first and wait a moment for it to initialize
-    # This isn't perfect, but if the health check catches PostgreSQL when it's
-    # first being initialized, the agent can fail to connect.
-    # A better solution would probably be to make the agent retry more.
-    docker compose up -d db
-
-    sleep 2
-
     # Start the containers
     docker compose up --exit-code-from=agent agent
     rc=$?