fix: avoid adding phonon4qt5-backend-gstreamer repeatedly

phonon4qt5-backend-gstreamer added in :
https://github.com/RadxaOS-SDK/rsdk/blob/main/src/share/rsdk/build/mod/packages/kde.libjsonnet#L79-L92

fixed: #126

Signed-off-by: Jiali Chen <chenjiali@radxa.com>

Author: CodeChenL

src/share/rsdk/build/mod/packages/kde.libjsonnet

@@ -38,7 +38,6 @@ function(suite,
             "kwin-x11",
             "libkf5kdelibs4support5",
             "libkf5kdelibs4support5-bin",
-            "phonon4qt5-backend-gstreamer",
             "phonon4qt5-backend-vlc",
             "phonon4qt5settings",
             "plasma-discover",