/usr/lib/ is in libkf5plasma-dev 5.28.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/KF5PlasmaConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/KF5PlasmaConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/KF5PlasmaMacros.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/KF5PlasmaTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5Plasma/KF5PlasmaTargets.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5PlasmaQuick/
/usr/lib/x86_64-linux-gnu/cmake/KF5PlasmaQuick/KF5PlasmaQuickConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5PlasmaQuick/KF5PlasmaQuickConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5PlasmaQuick/KF5PlasmaQuickTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5PlasmaQuick/KF5PlasmaQuickTargets.cmake
/usr/lib/x86_64-linux-gnu/libKF5Plasma.so
/usr/lib/x86_64-linux-gnu/libKF5PlasmaQuick.so