fix: windows tests for all cases (#9594)

Replaces #9299

cmd/object-api-input-checks.go

@@ -18,6 +18,8 @@ package cmd
 
 import (
 	"context"
+	"runtime"
+	"strings"
 
 	"github.com/google/uuid"
 	"github.com/minio/minio-go/v6/pkg/s3utils"
@@ -50,6 +52,10 @@ func checkBucketAndObjectNames(ctx context.Context, bucket, object string) error
 		logger.LogIf(ctx, ObjectNameInvalid{Bucket: bucket, Object: object})
 		return ObjectNameInvalid{Bucket: bucket, Object: object}
 	}
+	if runtime.GOOS == globalWindowsOSName && strings.Contains(object, "\\") {
+		// Objects cannot be contain \ in Windows and is listed as `Characters to Avoid`.
+		return ObjectNameInvalid{Bucket: bucket, Object: object}
+	}
 	return nil
 }