fix: avoid deleting peers on graceful close (#14165)

* fix: avoid deleting peers on graceful close

- Fixes an issue where a coordinator deletes all
  its peers on shutdown. This can cause disconnects
  whenever a coderd is redeployed.

coderd/database/dbtestutil/db.go

@@ -35,6 +35,7 @@ type options struct {
 	dumpOnFailure bool
 	returnSQLDB   func(*sql.DB)
 	logger        slog.Logger
+	url           string
 }
 
 type Option func(*options)
@@ -59,6 +60,12 @@ func WithLogger(logger slog.Logger) Option {
 	}
 }
 
+func WithURL(u string) Option {
+	return func(o *options) {
+		o.url = u
+	}
+}
+
 func withReturnSQLDB(f func(*sql.DB)) Option {
 	return func(o *options) {
 		o.returnSQLDB = f
@@ -92,6 +99,9 @@ func NewDB(t testing.TB, opts ...Option) (database.Store, pubsub.Pubsub) {
 	ps := pubsub.NewInMemory()
 	if WillUsePostgres() {
 		connectionURL := os.Getenv("CODER_PG_CONNECTION_URL")
+		if connectionURL == "" && o.url != "" {
+			connectionURL = o.url
+		}
 		if connectionURL == "" {
 			var (
 				err     error