Update Web Player v3
- beta.6 https://github.com/podlove/podlove-web-player/releases/tag/v3.0.0-beta.6
- rc.1 https://github.com/podlove/podlove-web-player/releases/tag/v3.0.0-rc.1
- rc.2 https://github.com/podlove/podlove-web-player/releases/tag/v3.0.0-rc2
- rc.3 https://github.com/podlove/podlove-web-player/releases/tag/v3.0.0-rc3