/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/ is in libqt5waylandclient5-dev 5.9.5-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClientConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClientConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_DrmEglServerBufferPlugin.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_QWaylandBradientDecorationPlugin.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_QWaylandEglClientBufferPlugin.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_QWaylandIviShellIntegrationPlugin.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_QWaylandXCompositeEglClientBufferPlugin.cmake
/usr/lib/x86_64-linux-gnu/cmake/Qt5WaylandClient/Qt5WaylandClient_QWaylandXCompositeGlxClientBufferPlugin.cmake