feat: port GPU code to CUDA 13 and enable GPU computation

Major changes:
   - Update makefile.inc for CUDA 13.1 with sm_89 architecture (RTX 4050)
   - Replace deprecated cudaThreadSynchronize() with cudaDeviceSynchronize()
   - Add CUDA_SAFE_CALL macro for CUDA 13 compatibility
   - Fix duplicate function definitions (compare_result_gpu, SHStep)
   - Fix syntax error in bssn_step_gpu.C
   - Enable GPU calculation in AMSS_NCKU_Input.py
   - Successfully build ABEGPU executable

AMSS_NCKU_source/bssn_step_gpu.C

@@ -1676,8 +1676,11 @@ void bssn_class::Step_GPU(int lev, int YN)
 #endif // PSTR == ?
 
 //--------------------------With Shell--------------------------
+// Note: SHStep() implementation is in bssn_gpu_class.C
 
 #ifdef WithShell
+#if 0
+// This SHStep() implementation has been moved to bssn_gpu_class.C to avoid duplicate definition
 void bssn_class::SHStep()
 {
   int lev = 0;
@@ -1938,5 +1941,5 @@ void bssn_class::SHStep()
     sPp = sPp->next;
   }
 }
-d
+#endif // #if 0
 #endif // withshell