Add temporary docs for install of new Qt7 requirements

This will eventually be bundled in AppImage and then this will no longer be needed

docs/en/qgc-user-guide/getting_started/download_and_install.md

@@ -64,8 +64,8 @@ Before installing _QGroundControl_ for the first time:
    sudo usermod -a -G dialout $USER
    sudo apt-get remove modemmanager -y
    sudo apt install gstreamer1.0-plugins-bad gstreamer1.0-libav gstreamer1.0-gl -y
-   sudo apt install libqt5gui5 -y
    sudo apt install libfuse2 -y
+   sudo apt install libxcb-xinerama0 libxkbcommon-x11-0 libxcb-cursor0 -y
    ```
    <!-- Note, remove install of libqt5gui5 https://github.com/mavlink/qgroundcontrol/issues/10176 fixed -->
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