Remove legacy webrtc provider APIs

[allenporter]

Breaking change

Breaking change for developers: This removes the legacy WebRTC provider API async_register_rtsp_to_web_rtc_provider in favor of the new WebRTC provider APIs introduced while adding go2rtc

Integrations now use the package homeassistant.components.camera.webrtc and implement CameraWebRTCProvider and register with async_register_webrtc_provider.

Proposed change

Remove legacy webrtc provider APIs and update rtsp_to_webrtc to use the new APIs.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: Update WebRTC provider documentation to reference new APIs. developers.home-assistant#2410

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[home-assistant]

Hey there @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (camera) you are listed as a code owner for? Thanks!

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[edenhaus]

Drafting this PR as I will discuss it with the core team to discuss if we can really remove the API without any deprecation period.
In my opinion, also, this PR should be merged after #127981. Otherwise, #127981 will get even bigger as we need to add support for async webRTC and especially async candidates in the mentioned PR.

[allenporter]

Drafting this PR as I will discuss it with the core team to discuss if we can really remove the API without any deprecation period. In my opinion, also, this PR should be merged after #127981. Otherwise, #127981 will get even bigger as we need to add support for async webRTC and especially async candidates in the mentioned PR.

My take is that it gets smaller by removing the shim layer support. There is already too much complexity in camera for special cases and I think it's work minimizing. Open to input of course, but that's my recommendation.

[allenporter]

Drafting this PR as I will discuss it with the core team to discuss if we can really remove the API without any deprecation period. In my opinion, also, this PR should be merged after #127981. Otherwise, #127981 will get even bigger as we need to add support for async webRTC and especially async candidates in the mentioned PR.

My take is that it gets smaller by removing the shim layer support. There is already too much complexity in camera for special cases and I think it's work minimizing. Open to input of course, but that's my recommendation.

Either way, whatever it takes to move fast here -- My impression is we're blocked until tuesday when frontend gets sorted.