Ignore CLR_DOTNET_RID when using stub cdac (#114541)

Author: am11

src/coreclr/debug/runtimeinfo/CMakeLists.txt

@@ -42,7 +42,7 @@ install_clr(TARGETS runtimeinfo DESTINATIONS lib COMPONENT runtime)
 
 # cDAC contract descriptor
 
-if("${CLR_DOTNET_RID}" STREQUAL "")
+if(CDAC_BUILD_TOOL_BINARY_PATH AND "${CLR_DOTNET_RID}" STREQUAL "")
   message(FATAL_ERROR "CLR_DOTNET_RID is not set. Please ensure it is being set to the portable RID of the target platform by runtime.proj.")
 endif()
 configure_file(configure.h.in ${CMAKE_CURRENT_BINARY_DIR}/configure.h)