chore(deps, cpp): update xwin to 0.6.7

Author: rjaegers

.devcontainer/cpp/Dockerfile

@@ -5,7 +5,7 @@ ARG CCACHE_VERSION=4.11
 ARG CLANG_VERSION=18
 ARG CPM_VERSION=0.40.2
 ARG INCLUDE_WHAT_YOU_USE_VERSION=0.22
-ARG XWIN_VERSION=0.6.5
+ARG XWIN_VERSION=0.6.7
 
 ARG DEBIAN_FRONTEND=noninteractive