Specify library name and version: qt/6.5.2

I've noticed that my statically built Qt6 on Windows failed when I set the qtmultimedia option.

From a quick glance at the code, I noticed that the default_options are frozen inside the configure(...) method, where the function that is supposed to be setting the module dependency options (like qtmultimedia should set qtshadertools) runs. This option setting fails with the error ConanException: Incorrect attempt to modify option 'qtshadertools' from 'False' to 'True'. This is documented in this issue.

As a quick fix, we can remove the default value of qtshadertools so it does not get frozen, allowing the _enablemodule calls in the recipe to succeed setting the dependencies from the qtmodules6.5.2.conf file as expected.

I also suspect that other module dependencies may be broken, as the freezing behaviour seems to be a breaking change from Conan 1.x as documented here. I haven't had time to build other optional Qt6 modules yet.

• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.