Fix concurrent map panic on inject metadata

Signed-off-by: Jin Dong <[email protected]>

example/go.mod

@@ -4,24 +4,24 @@ go 1.18
 
 require (
 	github.com/containerd/otelttrpc v0.0.0-00010101000000-000000000000
-	github.com/containerd/ttrpc v1.2.2
+	github.com/containerd/ttrpc v1.2.7
 	go.opentelemetry.io/otel v1.19.0
 	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.19.0
 	go.opentelemetry.io/otel/sdk v1.19.0
 	go.opentelemetry.io/otel/trace v1.19.0
-	google.golang.org/protobuf v1.31.0
+	google.golang.org/protobuf v1.33.0
 )
 
 require (
+	github.com/containerd/log v0.1.0 // indirect
 	github.com/go-logr/logr v1.3.0 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
-	github.com/sirupsen/logrus v1.8.1 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
 	go.opentelemetry.io/otel/metric v1.19.0 // indirect
-	golang.org/x/net v0.11.0 // indirect
-	golang.org/x/sys v0.14.0 // indirect
+	golang.org/x/sys v0.18.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230731190214-cbb8c96f2d6d // indirect
-	google.golang.org/grpc v1.57.0 // indirect
+	google.golang.org/grpc v1.57.1 // indirect
 )
 
 replace github.com/containerd/otelttrpc => ../