[SYCL] Disable errors from warnings while building the Unified Runtime (#8670)

Currently we disable warnings using specific set of options, some of
them are supported by GCC only. Also new warnings may appear in the
future and they will cause build failures and require another specific
options.

So just use more generic -Wno-error option instead to ignore all
warnings because unified runtime is external project.

Author: againull

sycl/plugins/unified_runtime/CMakeLists.txt

@@ -12,15 +12,11 @@ if (NOT DEFINED UNIFIED_RUNTIME_LIBRARY OR NOT DEFINED UNIFIED_RUNTIME_INCLUDE_D
     GIT_TAG           ${UNIFIED_RUNTIME_TAG}
   )
 
-  # Disable some compilation options to avoid errors while building the UR.
+  # Disable errors from warnings while building the UR.
   # And remember origin flags before doing that.
   set(CMAKE_CXX_FLAGS_BAK "${CMAKE_CXX_FLAGS}")
   if (UNIX)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-but-set-variable")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-pedantic")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-stringop-truncation")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-parameter")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-suggest-override")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error")
   endif()
 
   # No need to build tests from unified-runtime