[UR] remove duplicate ur files (#12417)

The ur.hpp and ur.cpp files were moved to the unified runtime repo.

This is currently blocking #12403,
oneapi-src/unified-runtime#1252.

sycl/plugins/unified_runtime/CMakeLists.txt

@@ -119,6 +119,8 @@ message(STATUS
   "Using Unified Runtime source directory: ${UNIFIED_RUNTIME_SOURCE_DIR}")
 
 set(UNIFIED_RUNTIME_INCLUDE_DIR "${UNIFIED_RUNTIME_SOURCE_DIR}/include")
+set(UNIFIED_RUNTIME_SRC_INCLUDE_DIR "${UNIFIED_RUNTIME_SOURCE_DIR}/source")
+set(UNIFIED_RUNTIME_COMMON_INCLUDE_DIR "${UNIFIED_RUNTIME_SOURCE_DIR}/source/common")
 
 add_library(UnifiedRuntimeLoader ALIAS ur_loader)
 add_library(UnifiedRuntimeCommon ALIAS ur_common)
@@ -148,6 +150,9 @@ set(UNIFIED_RUNTIME_PLUGIN_ARGS
     Threads::Threads
     UnifiedRuntimeLoader
     UnifiedRuntime-Headers
+  INCLUDE_DIRS
+    "${UNIFIED_RUNTIME_SRC_INCLUDE_DIR}"
+    "${UNIFIED_RUNTIME_COMMON_INCLUDE_DIR}"
 )
 
 # We need for #include <ze_api.h> in common.h