Get rid of lxqt-qtplugin

It is stil impossible to build it statically and it seems that reading icon theme from gtk is pretty enough

.gitmodules

@@ -82,12 +82,6 @@
 [submodule "Telegram/ThirdParty/qt5ct"]
 	path = Telegram/ThirdParty/qt5ct
 	url = https://github.com/desktop-app/qt5ct.git
-[submodule "Telegram/ThirdParty/lxqt-qtplugin"]
-	path = Telegram/ThirdParty/lxqt-qtplugin
-	url = https://github.com/lxqt/lxqt-qtplugin.git
-[submodule "Telegram/ThirdParty/libqtxdg"]
-	path = Telegram/ThirdParty/libqtxdg
-	url = https://github.com/lxqt/libqtxdg.git
 [submodule "Telegram/ThirdParty/fcitx5-qt"]
 	path = Telegram/ThirdParty/fcitx5-qt
 	url = https://github.com/fcitx/fcitx5-qt.git

Telegram/CMakeLists.txt

@@ -112,14 +112,6 @@ if (LINUX)
     )
 
     if (NOT DESKTOP_APP_DISABLE_DBUS_INTEGRATION)
-        # conflicts with Qt static link
-        if (DESKTOP_APP_USE_PACKAGED_LAZY_PLATFORMTHEMES)
-            target_link_libraries(Telegram
-            PRIVATE
-                desktop-app::external_lxqt_qtplugin
-            )
-        endif()
-
         target_link_libraries(Telegram
         PRIVATE
             desktop-app::external_statusnotifieritem

Telegram/SourceFiles/qt_static_plugins.cpp

@@ -62,11 +62,4 @@ Q_IMPORT_PLUGIN(QHimePlatformInputContextPlugin)
 Q_IMPORT_PLUGIN(Qt5CTPlatformThemePlugin)
 Q_IMPORT_PLUGIN(Qt5CTStylePlugin)
 #endif // !DESKTOP_APP_USE_PACKAGED || DESKTOP_APP_USE_PACKAGED_LAZY_PLATFORMTHEMES
-
-// conflicts with Qt static link
-#ifdef DESKTOP_APP_USE_PACKAGED_LAZY_PLATFORMTHEMES
-#ifndef DESKTOP_APP_DISABLE_DBUS_INTEGRATION
-Q_IMPORT_PLUGIN(LXQtPlatformThemePlugin)
-#endif // !DESKTOP_APP_DISABLE_DBUS_INTEGRATION
-#endif // DESKTOP_APP_USE_PACKAGED_LAZY_PLATFORMTHEMES
 #endif // Q_OS_UNIX && !Q_OS_MAC