Make tests more reliable (#2948)

When using `testrig.CreateBase` and then using that base for other
`NewInternalAPI` calls, we never actually shutdown the components.
`testrig.CreateBase` returns a `close` function, which only removes the
database, so still running components have issues connecting to the
database, since we ripped it out underneath it - which can result in
"Disk I/O" or "pq deadlock detected" issues.

federationapi/federationapi.go

@@ -85,10 +85,7 @@ func AddPublicRoutes(
 	}
 
 	routing.Setup(
-		base.PublicFederationAPIMux,
-		base.PublicKeyAPIMux,
-		base.PublicWellKnownAPIMux,
-		cfg,
+		base,
 		rsAPI, f, keyRing,
 		federation, userAPI, keyAPI, mscCfg,
 		servers, producer,