kubelet: DRA: Handle grpc.ErrServerStopped in plugin tests

Update setupFakeGRPCServer to ignore grpc.ErrServerStopped when serving
the gRPC test server. This prevents unnecessary panics during server
shutdown and ensures clean test teardown. The change improves test
stability by allowing expected server stop errors to be handled gracefully.

pkg/kubelet/cm/dra/plugin/dra_plugin_test.go

@@ -18,6 +18,7 @@ package plugin
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
 	"path"
@@ -80,7 +81,7 @@ func setupFakeGRPCServer(service, addr string) (tearDown, error) {
 
 	go func() {
 		go func() {
-			if err := s.Serve(listener); err != nil {
+			if err := s.Serve(listener); err != nil && !errors.Is(err, grpc.ErrServerStopped) {
 				panic(err)
 			}
 		}()