chore(v4.2.x): release 4.2.8

[github-actions]

🤖 I have created a release beep boop

4.2.8 (2023-01-31)

Bug Fixes

• Add mux.js to support.html (#4923) (4c46595)
• DASH: Fix dynamic manifests from edgeware (#4914) (247229b)
• Fix MediaCapabilities polyfill on Hisense (#4927) (8b694f0)
• Fix WebVTT parser failure on REGION blocks (#4915) (39ba2e8)
• HLS: Fix detection of WebVTT subtitles in HLS by extension (#4928) (b0eb356), closes #4929
• VTT: Fix combining style selectors (#4934) (c036c53)
• WebVTT: Add support to  , ‎ and ‏ (#4920) (3fa6ff0)
• WebVTT: Add support to voice tag styles (#4845) (e8465a2)
• WebVTT: Fix horizontal positioning with cue box size (#4949) (74d399d)
• WebVTT: Fix voices with styles and support to multiple styles (#4922) (355a59f)

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[github-actions]

🤖 Release is at https://github.com/shaka-project/shaka-player/releases/tag/v4.2.8 🌻