Use hass httpx client for ElevenLabs component

[sorgfresser]

Proposed change

Use the Httpx Client by Hass instead of the default one of the elevenlabs python sdk to stop blocking HomeAssistant's event loop.

I am not quite sure whether I can really test this behaviour in pytest, but the tests cover that at least no major issue is introduced and I verified locally that this resolves the warnings.

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 elevenlabs - Detected blocking call to load_verify_locations with args #126669

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[frenck]

Thanks, @sorgfresser 👍

../Frenck