chore(v4.3.x): release 4.3.7

[github-actions]

🤖 I have created a release beep boop

4.3.7 (2023-06-21)

Bug Fixes

• CEA 608 captions not work with H.265 video streams (#5252) (b08bb41), closes #5251
• Demo: Fix deployment of codem-isoboxer in the Demo (#5257) (7e2903a)
• demo: Fix deployment of v4.3.x on appspot (ccf5e2e)
• Demo: Fix error link width to avoid overlap with close button (#5309) (f575dab)
• Fix error when network status changes on src= playbacks (#5305) (cf683f5)
• HLS: Avoid "Possible encoding problem detected!" when is a preload reference (#5332) (9ce8cc0)
• HLS: Avoid HLS resync when there is a gap in the stream (#5284) (679dbae)
• HLS: Avoid variable substitution if no variables (#5269) (49afa92)
• HLS: Fix HLS seekRange for live streams (#5263) (03df9cb)
• HLS: Fix seekRange for EVENT playlist not using EXT-X-PLAYLIST-TYPE (#5220) (562831b)
• HLS: Parse EXT-X-PART-INF as media playlist tag (#5311) (f6210ee)
• HLS: Skip EXT-X-PRELOAD-HINT without full byterange info (#5294) (9e193e2)
• media source object URL revocation (#5214) (1a89daa)
• Ship to NPM without node version restrictions (#5253) (ca096a8), closes #5243
• unnecessary parsing of in-band pssh when pssh is in the manifest (#5198) (8d6494d)

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[CHaNGeTe]

@joeyparrish can we push this somehow?
I believe the CLA check is reporting a wrong status because is asking for the automation bot to sign the CLA
btw, do we have matching version for 5.x release?

[JulianDomingo]

Joey caught a missing appspot dependency for this branch (ccf5e2e), which needed to be addressed before merging the latest v.4.3.x branch.

[github-actions]

🤖 Release is at https://github.com/shaka-project/shaka-player/releases/tag/v4.3.7 🌻