CMake deploy api and QtMultimedia backend

I am using the cmake-deployment-api to deploy a qt application.

The application built by the machine works ok.

But when using the application deployed by the cmake API, the application returns

could not load multimedia backend ""
QtMultimedia is not currently supported on this platform or compiler. 

After some [discussion](https://forum.qt.io/post/774004) on the forum, I have realized that

libffmpegmediaplugin.so  libgstreamermediaplugin.so 

are not deployed by the API in Linux.

To recreate the issue I have created a [repo](https://github.com/EddyTheCo/BugReportMultimedia/tree/v0.0.1).

On the [releases] (https://github.com/EddyTheCo/BugReportMultimedia/releases/tag/v0.0.1)

(using Qt 6.6.0) one can see that the [backend](https://doc.qt.io/qt-6/qtmultimedia-index.html#backends) libraries are not deployed for Linux.

Also Using Qt 6.7.0 on linux the backend libraries are not deployed for Linux.

If I add in the root CMakeLists.txt

find_package(Qt6 REQUIRED COMPONENTS Core Gui Quick Qml Multimedia)

The multimedia backends are deployed and the application works ok.
But ideally, my application does not have to know about the dependencies of one of its libraries.