Fix S3 client credentials to use environment variables

The test was using hardcoded credentials "any"/"any" but the Makefile
sets AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY to "some_access_key1"/
"some_secret_key1". Updated getS3Client() to read from environment
variables with fallback to "any"/"any" for manual testing.

test/s3/sse/s3_volume_encryption_test.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"os"
 	"strings"
 	"testing"
 	"time"
@@ -399,12 +400,23 @@ func TestS3VolumeEncryptionCopy(t *testing.T) {
 // Helper functions
 
 func getS3Client(t *testing.T) *s3.S3 {
+	// Use credentials from environment if available, otherwise use defaults
+	// This allows tests to work with the Makefile which sets AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY
+	accessKey := "any"
+	secretKey := "any"
+	if envAccessKey := os.Getenv("AWS_ACCESS_KEY_ID"); envAccessKey != "" {
+		accessKey = envAccessKey
+	}
+	if envSecretKey := os.Getenv("AWS_SECRET_ACCESS_KEY"); envSecretKey != "" {
+		secretKey = envSecretKey
+	}
+
 	sess, err := session.NewSession(&aws.Config{
 		Region:           aws.String("us-east-1"),
 		Endpoint:         aws.String("http://localhost:8333"),
 		DisableSSL:       aws.Bool(true),
 		S3ForcePathStyle: aws.Bool(true),
-		Credentials:      credentials.NewStaticCredentials("any", "any", ""),
+		Credentials:      credentials.NewStaticCredentials(accessKey, secretKey, ""),
 	})
 	if err != nil {
 		t.Fatalf("Failed to create session: %v", err)