[SYCL][Graph] Remove calls to urCommandBufferReleaseCommandExp

Reflects UR change from oneapi-src/unified-runtime#2578
where we no longer need to manually manage the lifetimes of the
individual commands in a UR command-buffer.

Author: EwanC

sycl/cmake/modules/FetchUnifiedRuntime.cmake

@@ -116,7 +116,7 @@ if(SYCL_UR_USE_FETCH_CONTENT)
       CACHE PATH "Path to external '${name}' adapter source dir" FORCE)
   endfunction()
 
-  set(UNIFIED_RUNTIME_REPO "https://github.com/oneapi-src/unified-runtime.git")
+  set(UNIFIED_RUNTIME_REPO "https://github.com/Bensuo/unified-runtime.git")
   include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules/UnifiedRuntimeTag.cmake)
 
   set(UMF_BUILD_EXAMPLES OFF CACHE INTERNAL "EXAMPLES")

sycl/cmake/modules/UnifiedRuntimeTag.cmake

@@ -4,4 +4,4 @@
 # Date:   Thu Jan 16 14:30:47 2025 +0000
 #     Merge pull request #2569 from zhaomaosu/asan-only-warn-host-ptr
 #     [DevASAN] Only report warning if passing host ptr to kernel
-set(UNIFIED_RUNTIME_TAG eaea885d5477c8936209175a5b00062ca44f5765)
+set(UNIFIED_RUNTIME_TAG "ewan/remove_command_ref_counting")

sycl/source/detail/graph_impl.cpp

@@ -951,15 +951,6 @@ exec_graph_impl::~exec_graph_impl() {
         }
       }
     }
-
-    for (auto &Iter : MCommandMap) {
-      if (auto Command = Iter.second; Command) {
-        ur_result_t Res = Adapter->call_nocheck<
-            sycl::detail::UrApiKind::urCommandBufferReleaseCommandExp>(Command);
-        (void)Res;
-        assert(Res == UR_RESULT_SUCCESS);
-      }
-    }
   } catch (std::exception &e) {
     __SYCL_REPORT_EXCEPTION_TO_STREAM("exception in ~exec_graph_impl", e);
   }