[Breaking] Switch from rabit to the collective communicator (#8257)

* Switch from rabit to the collective communicator

* fix size_t specialization

* really fix size_t

* try again

* add include

* more include

* fix lint errors

* remove rabit includes

* fix pylint error

* return dict from communicator context

* fix communicator shutdown

* fix dask test

* reset communicator mocklist

* fix distributed tests

* do not save device communicator

* fix jvm gpu tests

* add python test for federated communicator

* Update gputreeshap submodule

Co-authored-by: Hyunsu Philip Cho <chohyu01@cs.washington.edu>

src/metric/survival_metric.cu

@@ -5,7 +5,6 @@
  * \author Avinash Barnwal, Hyunsu Cho and Toby Hocking
  */
 
-#include <rabit/rabit.h>
 #include <dmlc/registry.h>
 
 #include <memory>
@@ -16,6 +15,7 @@
 #include "xgboost/host_device_vector.h"
 
 #include "metric_common.h"
+#include "../collective/communicator-inl.h"
 #include "../common/math.h"
 #include "../common/survival_util.h"
 #include  "../common/threading_utils.h"
@@ -214,7 +214,7 @@ template <typename Policy> struct EvalEWiseSurvivalBase : public Metric {
                                   info.labels_upper_bound_, preds);
 
     double dat[2]{result.Residue(), result.Weights()};
-    rabit::Allreduce<rabit::op::Sum>(dat, 2);
+    collective::Allreduce<collective::Operation::kSum>(dat, 2);
     return Policy::GetFinal(dat[0], dat[1]);
   }