chore(ci): Add redis 8.4-RC1-pre & examples (#3572)

* add disable maintnotifications example

* add 8.4-RC1-pre

* println -> printf for linter

* address jit comment

example/disable-maintnotifications/main.go

@@ -0,0 +1,144 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+	"github.com/redis/go-redis/v9/maintnotifications"
+)
+
+func main() {
+	ctx := context.Background()
+
+	// Example 0: Explicitly disable maintenance notifications
+	fmt.Println("=== Example 0: Explicitly Enabled ===")
+	rdb0 := redis.NewClient(&redis.Options{
+		Addr: "localhost:6379",
+
+		// Explicitly disable maintenance notifications
+		// This prevents the client from sending CLIENT MAINT_NOTIFICATIONS ON
+		MaintNotificationsConfig: &maintnotifications.Config{
+			Mode: maintnotifications.ModeEnabled,
+		},
+	})
+	defer rdb0.Close()
+
+	// Test the connection
+	if err := rdb0.Ping(ctx).Err(); err != nil {
+		fmt.Printf("Failed to connect: %v\n\n", err)
+	}
+	fmt.Println("When ModeEnabled, the client will return an error if the server doesn't support maintenance notifications.")
+	fmt.Printf("ModeAuto will silently disable the feature.\n\n")
+
+	// Example 1: Explicitly disable maintenance notifications
+	fmt.Println("=== Example 1: Explicitly Disabled ===")
+	rdb1 := redis.NewClient(&redis.Options{
+		Addr: "localhost:6379",
+
+		// Explicitly disable maintenance notifications
+		// This prevents the client from sending CLIENT MAINT_NOTIFICATIONS ON
+		MaintNotificationsConfig: &maintnotifications.Config{
+			Mode: maintnotifications.ModeDisabled,
+		},
+	})
+	defer rdb1.Close()
+
+	// Test the connection
+	if err := rdb1.Ping(ctx).Err(); err != nil {
+		fmt.Printf("Failed to connect: %v\n\n", err)
+		return
+	}
+	fmt.Println("✓ Connected successfully (maintenance notifications disabled)")
+
+	// Perform some operations
+	if err := rdb1.Set(ctx, "example:key1", "value1", 0).Err(); err != nil {
+		fmt.Printf("Failed to set key: %v\n\n", err)
+		return
+	}
+	fmt.Println("✓ SET operation successful")
+
+	val, err := rdb1.Get(ctx, "example:key1").Result()
+	if err != nil {
+		fmt.Printf("Failed to get key: %v\n\n", err)
+		return
+	}
+	fmt.Printf("✓ GET operation successful: %s\n\n", val)
+
+	// Example 2: Using nil config (defaults to ModeAuto)
+	fmt.Printf("\n=== Example 2: Default Behavior (ModeAuto) ===\n")
+	rdb2 := redis.NewClient(&redis.Options{
+		Addr: "localhost:6379",
+		// MaintNotifications: nil means ModeAuto (enabled for Redis Cloud)
+	})
+	defer rdb2.Close()
+
+	if err := rdb2.Ping(ctx).Err(); err != nil {
+		fmt.Printf("Failed to connect: %v\n\n", err)
+		return
+	}
+	fmt.Println("✓ Connected successfully (maintenance notifications auto-enabled)")
+
+	// Example 4: Comparing behavior with and without maintenance notifications
+	fmt.Printf("\n=== Example 4: Performance Comparison ===\n")
+
+	// Client with auto-enabled notifications
+	startauto := time.Now()
+	for i := 0; i < 1000; i++ {
+		key := fmt.Sprintf("test:auto:%d", i)
+		if err := rdb2.Set(ctx, key, i, time.Minute).Err(); err != nil {
+			fmt.Printf("Failed to set key: %v\n", err)
+			return
+		}
+	}
+	autoDuration := time.Since(startauto)
+	fmt.Printf("✓ 1000 SET operations (auto): %v\n", autoDuration)
+
+	// print pool stats
+	fmt.Printf("Pool stats (auto): %+v\n", rdb2.PoolStats())
+
+	// give the server a moment to take chill
+	fmt.Println("---")
+	time.Sleep(time.Second)
+
+	// Client with disabled notifications
+	start := time.Now()
+	for i := 0; i < 1000; i++ {
+		key := fmt.Sprintf("test:disabled:%d", i)
+		if err := rdb1.Set(ctx, key, i, time.Minute).Err(); err != nil {
+			fmt.Printf("Failed to set key: %v\n", err)
+			return
+		}
+	}
+	disabledDuration := time.Since(start)
+	fmt.Printf("✓ 1000 SET operations (disabled): %v\n", disabledDuration)
+	fmt.Printf("Pool stats (disabled): %+v\n", rdb1.PoolStats())
+
+	// performance comparison note
+	fmt.Printf("\nNote: The pool stats and performance are identical because there is no background processing overhead.\n")
+	fmt.Println("Since the server doesn't support maintenance notifications, there is no difference in behavior.")
+	fmt.Printf("The only difference is that the \"ModeDisabled\" client doesn't send the CLIENT MAINT_NOTIFICATIONS ON command.\n\n")
+	fmt.Println("p.s. reordering the execution here makes it look like there is a small performance difference, but it's just noise.")
+
+	// Cleanup
+	fmt.Printf("\n=== Cleanup ===\n")
+	if err := rdb1.FlushDB(ctx).Err(); err != nil {
+		fmt.Printf("Failed to flush DB: %v\n", err)
+		return
+	}
+	fmt.Println("✓ Database flushed")
+
+	fmt.Printf("\n=== Summary ===\n")
+	fmt.Println("Maintenance notifications can be disabled by setting:")
+	fmt.Println("  MaintNotifications: &maintnotifications.Config{")
+	fmt.Println("    Mode: maintnotifications.ModeDisabled,")
+	fmt.Println("  }")
+	fmt.Printf("\nThis is useful when:\n")
+	fmt.Println("  - Connecting to non-Redis Cloud instances")
+	fmt.Println("  - You want to handle failovers manually")
+	fmt.Println("  - You want to minimize client-side overhead")
+	fmt.Println("  - The Redis server doesn't support CLIENT MAINT_NOTIFICATIONS")
+	fmt.Printf("\nFor more information, see:\n")
+	fmt.Println("  https://github.com/redis/go-redis/tree/master/maintnotifications")
+}