* infra: Migrate to .NET 6

* Rollback version naming change

* Workaround .NET 6 ZipArchive API issues

* ci: Switch to VS 2022 for AppVeyor

CI is now ready for .NET 6

* Suppress WebClient warning in DoUpdateWithMultipleThreads

* Attempt to workaround System.Drawing.Common changes on 6.0.0

* Change keyboard rendering from System.Drawing to ImageSharp

* Make the software keyboard renderer multithreaded

* Bump ImageSharp version to 1.0.4 to fix a bug in Image.Load

* Add fallback fonts to the keyboard renderer

* Fix warnings

* Address caian's comment

* Clean up linux workaround as it's uneeded now

* Update readme

Co-authored-by: Caian Benedicto <caianbene@gmail.com>

* Haydn: Part 1

Based on my reverse of audio 11.0.0.

As always, core implementation under LGPLv3 for the same reasons as for Amadeus.

This place the bases of a more flexible audio system while making audout & audin accurate.

This have the following improvements:
- Complete reimplementation of audout and audin.
- Audin currently only have a dummy backend.
- Dramatically reduce CPU usage by up to 50% in common cases (SoundIO and OpenAL).
- Audio Renderer now can output to 5.1 devices when supported.
- Audio Renderer init its backend on demand instead of keeping two up all the time.
- All backends implementation are now in their own project.
- Ryujinx.Audio.Renderer was renamed Ryujinx.Audio and was refactored because of this.

As a note, games having issues with OpenAL haven't improved and will not
because of OpenAL design (stopping when buffers finish playing causing
possible audio "pops" when buffers are very small).

* Update for latest hexkyz's edits on Switchbrew

* audren: Rollback channel configuration changes

* Address gdkchan's comments

* Fix typo in OpenAL backend driver

* Address last comments

* Fix a nit

* Address gdkchan's comments