Make objdetect/test C++11-compliant and reproducible

- Add conditional compilation directives to replace deprecated std::random_shuffle with new std::shuffle when C++11 is available.

- Set random seed to a fixed value before shuffling containers to ensure reproducibility.

Resolves opencv/opencv#22209.

modules/objdetect/test/test_precomp.hpp

@@ -8,4 +8,10 @@
 #include "opencv2/objdetect.hpp"
 #include "opencv2/objdetect/objdetect_c.h"
 
+#if defined CV_CXX11
+  #include <random>
+#else
+  #include <cstdlib>
+#endif
+
 #endif