Update module github.com/prometheus/client_model to v0.6.1

vendor/google.golang.org/protobuf/runtime/protoiface/methods.go

@@ -103,6 +103,7 @@ type UnmarshalInput = struct {
 		FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error)
 		FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error)
 	}
+	Depth int
 }
 
 // UnmarshalOutput is output from the Unmarshal method.