raft: fix for mock send test in v3.6

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

Author: tonistiigi

manager/state/raft/transport/mock_raft_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"net"
+	"slices"
 	"time"
 
 	"github.com/moby/swarmkit/v2/api"
@@ -130,7 +131,7 @@ func (r *mockRaft) StreamRaftMessage(stream api.Raft_StreamRaftMessageServer) er
 		}
 
 		// Append received snapshot chunk to the chunk that was already received.
-		assembledMessage.Message.Snapshot.Data = append(assembledMessage.Message.Snapshot.Data, recvdMsg.Message.Snapshot.Data...)
+		assembledMessage.Message.Snapshot.Data = slices.Concat(assembledMessage.Message.Snapshot.Data, recvdMsg.Message.Snapshot.Data)
 	}
 
 	// We should have the complete snapshot. Verify and process.

manager/state/raft/transport/transport_test.go

@@ -11,10 +11,12 @@ import (
 	"go.etcd.io/raft/v3/raftpb"
 )
 
+const testSnapSize = 1 << 20 // 1 MB
+
 // Build a snapshot message where each byte in the data is of the value (index % sizeof(byte))
 func newSnapshotMessage(from uint64, to uint64) raftpb.Message {
-	data := make([]byte, GRPCMaxMsgSize)
-	for i := 0; i < GRPCMaxMsgSize; i++ {
+	data := make([]byte, testSnapSize)
+	for i := 0; i < testSnapSize; i++ {
 		data[i] = byte(i % (1 << 8))
 	}