Move not loaded websocket constant to zwave_js

[MartinHjelmare]

Breaking change

Proposed change

• Move this constant to zwave_js integration. It was introduced in Fix zwave_js websocket api KeyError on unloaded entry #50154.

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)
• 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: Fix zwave_js websocket api KeyError on unloaded entry #50154
• Link to documentation pull request:

Checklist

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