fix typo in boost::asio configuration

Author: ericniebler

CMakeLists.txt

@@ -416,7 +416,7 @@ set(STDEXEC_ASIO_IMPLEMENTATION "boost" CACHE STRING "boost")
 set_property(CACHE STDEXEC_ASIO_IMPLEMENTATION PROPERTY STRINGS boost standalone)
 
 if(STDEXEC_ENABLE_ASIO)
-    set(STDEXEC_ASIO_USES_ASIO FALSE)
+    set(STDEXEC_ASIO_USES_BOOST FALSE)
     set(STDEXEC_ASIO_USES_STANDALONE FALSE)
 
     include(rapids-find)