fix: log WARN on ErrConnectionClosed in tailnet.Controller.Run (#22293)

tailnet/controllers.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"maps"
 	"math"
+	"net"
 	"net/netip"
 	"slices"
 	"strings"
@@ -1433,6 +1434,11 @@ func (c *Controller) Run(ctx context.Context) {
 					return
 				}
 
+				if errors.Is(err, net.ErrClosed) {
+					c.logger.Warn(c.ctx, "control plane connection closed, retrying", slog.Error(err))
+					continue
+				}
+
 				// If the database is unreachable by the control plane, there's not much we can do, so we'll just retry later.
 				if errors.Is(err, codersdk.ErrDatabaseNotReachable) {
 					c.logger.Warn(c.ctx, "control plane lost connection to database, retrying",