[breaking] Remove the predictor param, allow fallback to prediction using DMatrix. (#9129)

- A `DeviceOrd` struct is implemented to indicate the device. It will eventually replace the `gpu_id` parameter.
- The `predictor` parameter is removed.
- Fallback to `DMatrix` when `inplace_predict` is not available.
- The heuristic for choosing a predictor is only used during training.

src/objective/lambdarank_obj.cu

@@ -577,8 +577,8 @@ void LambdaRankUpdatePositionBias(Context const* ctx, linalg::VectorView<double
                        if (lj(0) >= Eps64()) {
                          tj_minus(i) = std::pow(lj(i) / lj(0), regularizer);
                        }
-                       assert(!std::isinf(ti_plus(i)));
-                       assert(!std::isinf(tj_minus(i)));
+                       assert(!isinf(ti_plus(i)));
+                       assert(!isinf(tj_minus(i)));
                      });
 }
 }  // namespace cuda_impl