We had used conan for opus before, but there was a bug in the AVX detection.
However we still had the Findopus.cmake file within the repository, but not used.
This patch reenables the Findopus helper and prefer the system wide installation of opus.
* Remove git submodules that will be loaded through conan
* Move custom Find modules to their own folder
* Use conan for downloading missing external dependencies
* CI: Change the yuzu source folder user to the user that the containers run on
* Attempt to remove dirty mingw build hack
* Install conan on the msvc build
* Only set release build type when using not using multi config generator
* Re-add qt bundled to workaround an issue with conan qt not downloading prebuilt binaries
* Add workaround for submodules that use legacy CMAKE variables
* Re-add USE_BUNDLED_QT on the msvc build bot
Tracks upstream opus, allowing the library to be easily updated. While
we're at it, we incorporate the CMakeLists.txt so that we have easy
control over the requirements of the build.
Markus Wick