Three build failures (qt6-sensors, sddm, kwin) all trace to
qtdeclarative's sysroot/ directory being missing after staging.
CMake config files reference absolute paths into that sysroot.
1. qt-sysroot.sh: add mkdir -p before ln -sf in
redbear_qt_ensure_dep_sysroots() so the parent directory is
created when the dependency sysroot was cleaned up.
2. sddm wayland-patch.sh: fix sed pattern to include LinguistTools
token that exists in the actual upstream CMakeLists.txt line.
Without it the sed silently fails to match, leaving
LinguistTools/Test/QuickTest as REQUIRED components.
3. qt6-sensors recipe.toml: source qt-sysroot.sh and call
redbear_qt_ensure_dep_sysroots() before cmake configure.
Previously the recipe only symlinked plugins/mkspecs/metatypes/
modules but never fixed up dependency sysroot paths, causing
Qt6::Qml INTERFACE_INCLUDE_DIRECTORIES to reference a
non-existent include path.
vasilito
b8b348b11e