metropolis/curator: fix race condition in tests

grpclog cannot be accessed concurrently with gRPC requests possibly
already running. Let's just remove this integration in tests.

Change-Id: I074c583baf3a7f87e76e7dde6080e3efdb19d5c8
Reviewed-on: https://review.monogon.dev/c/monogon/+/1828
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/node/core/curator/impl_leader_test.go b/metropolis/node/core/curator/impl_leader_test.go
index b55efe6..a87c45e 100644
--- a/metropolis/node/core/curator/impl_leader_test.go
+++ b/metropolis/node/core/curator/impl_leader_test.go
@@ -18,7 +18,6 @@
 	"go.etcd.io/etcd/tests/v3/integration"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/test/bufconn"
 	"google.golang.org/protobuf/proto"
 
@@ -63,7 +62,6 @@
 
 	// Start a single-node etcd cluster.
 	integration.BeforeTestExternal(t)
-	grpclog.SetLoggerV2(logtree.GRPCify(lt.MustLeveledFor("grpc")))
 	cluster := integration.NewClusterV3(t, &integration.ClusterConfig{
 		Size: 1,
 		LoggerBuilder: func(memberName string) *zap.Logger {