Switching to old version of rccl_float8 for ROCm versions earlier than 6.3 for backward compatibility. (#128)

Co-authored-by: Marzieh Berenjkoub <mberenjk@amd.com>

[ROCm/rccl-tests commit: 9076091602]

projects/rccl-tests/src/rccl_float8.h

@@ -40,7 +40,7 @@ typedef struct
 } rccl_bfloat8;
 
 // __cplusplus < 201103L || (!defined(__HIP_PLATFORM_AMD__) && !defined(__HIPCC__))
-#elif HIP_VERSION >= 60200000
+#elif HIP_VERSION >= 60300000
 
 #include <hip/hip_fp8.h>