chore: reduce log volume on server startup (#16608)

Addresses https://github.com/coder/coder/issues/16231.

This PR reduces the volume of logs we print after server startup in
order to surface the web UI URL better.

Here are the logs after the changes a couple of seconds after starting
the server:

<img width="868" alt="Screenshot 2025-02-18 at 16 31 32"
src="https://github.com/user-attachments/assets/786dc4b8-7383-48c8-a5c3-a997c01ca915"
/>

The warning is due to running a development site-less build. It wouldn't
show in a release build.

enterprise/cli/provisionerdaemonstart.go

@@ -236,10 +236,11 @@ func (r *RootCmd) provisionerDaemonStart() *serpent.Command {
 					ProvisionerKey: provisionerKey,
 				})
 			}, &provisionerd.Options{
-				Logger:         logger,
-				UpdateInterval: 500 * time.Millisecond,
-				Connector:      connector,
-				Metrics:        metrics,
+				Logger:              logger,
+				UpdateInterval:      500 * time.Millisecond,
+				Connector:           connector,
+				Metrics:             metrics,
+				ExternalProvisioner: true,
 			})
 
 			waitForProvisionerJobs := false