chore(v4.2.x): release 4.2.12

[github-actions]

🤖 I have created a release beep boop

4.2.12 (2023-07-21)

Bug Fixes

• DASH: Avoid "Possible encoding problem detected!" when appending chunked data (#5376) (ad9de15)
• demo: Fix deployment of v4.2.x on appspot (d8b2378)
• Demo: Trim custom manifestUri to avoid copy-paste errors (#5378) (d7d2bcb)
• docs: fix player configuration code in drm config tutorial (#5359) (c5e0f8b)
• DRM: broken keySystemsMapping due to multiple references of drmInfo (#5388) (8906548)
• Fix captions from MP4s with multiple trun boxes (#5422) (b41186e), closes #5328
• Fix DASH rejection of streams with ColourPrimaries and MatrixCoefficients (#5345) (e2968ca)
• Fix exception on Tizen due to unsupported Array method (#5429) (0fe4d5c)
• Fix failure when drivers lag behind browser (#5423) (30f464f)
• Gap jump at start when first jump lands in a new gap (#5408) (1ead685)
• gap jumping when gap exists at start position (#5384) (bd5bade)
• HLS: Add subtitle role when there are no roles (#5357) (c5a5ddb)
• HLS: Fix dvh1 and dvhe detection as video codec (#5364) (3373a41)
• HLS: Ignore segments with zero duration (#5371) (29b81ea)
• media: Fix region checking in livestreams (#5361) (007a259), closes #5213
• Populate HDR correctly (#5369) (db67d8d)
• prevent access to null config_ in SimpleAbrManager (#5362) (80973d7)
• UI: Fix resolution selection on src= (#5367) (b570e92)
• WebVTT: Add support to middle position (#5366) (6481e29)

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[joeyparrish]

Testing of v4.2.x is underway.

[github-actions]

🤖 Release is at https://github.com/shaka-project/shaka-player/releases/tag/v4.2.12 🌻