[MLIR][ExecutionEngine] don't leak -Wweak-vtables

I'm not 100% what this is used for in this lib but the compile flag leaks out and prevents (in certain compile scenarios) linking `mlir_c_runner_utils`.

Author: makslevental

mlir/lib/ExecutionEngine/SparseTensor/CMakeLists.txt

@@ -21,6 +21,6 @@ set_property(TARGET MLIRSparseTensorRuntime PROPERTY CXX_STANDARD 17)
 check_cxx_compiler_flag(-Wweak-vtables
   COMPILER_SUPPORTS_WARNING_WEAK_VTABLES)
 if(COMPILER_SUPPORTS_WARNING_WEAK_VTABLES)
-  target_compile_options(MLIRSparseTensorRuntime PUBLIC
+  target_compile_options(MLIRSparseTensorRuntime PRIVATE
     "-Wweak-vtables")
 endif()