Fix a tiny problem in winml.cmake (microsoft#23173)

### Description
CMake's
[target_link_libraries](https://cmake.org/cmake/help/latest/command/target_link_libraries.html#id2)
function accepts plain library name(like `re2`) or target name(like
`re2::re2`) or some other kinds of names. "plain library names" are
old-fashioned, for compatibility only. We should use target names.

### Motivation and Context
To make vcpkg work with winml build. See microsoft#23158

Author: snnn

cmake/winml.cmake

@@ -782,7 +782,7 @@ add_dependencies(winml_dll winml_api_native)
 add_dependencies(winml_dll winml_api_native_internal)
 
 # Link libraries
-target_link_libraries(winml_dll PRIVATE re2)
+target_link_libraries(winml_dll PRIVATE re2::re2)
 target_link_libraries(winml_dll PRIVATE ${WIL_TARGET})
 target_link_libraries(winml_dll PRIVATE winml_lib_api)
 if (NOT winml_is_inbox)