Make sure that exception flags are not overridden in syncqt tool

qt_internal_add_tool has the implicit logic that disregards the
previously installed flags and adds new flags that overrides the
exceptions behavior. Add the tool-specific option to make sure
that this won't happen.

Ammends 0f5fbe369b

Pick-to: 6.6 6.5
Change-Id: Id149d8d8002390581813475124ba37dd39d56b9b
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/tools/syncqt/CMakeLists.txt

@@ -32,6 +32,7 @@ qt_get_tool_target_name(target_name syncqt)
 if(NOT QT_SYNC_HEADERS_AT_CONFIGURE_TIME)
     qt_internal_add_tool(${target_name}
         DEFINES ${compile_definitions}
+        EXCEPTIONS
         TOOLS_TARGET Core
         CORE_LIBRARY None
         INSTALL_DIR "${INSTALL_LIBEXECDIR}"