Remove SUPPORT_WHITE_VALUE from ZHA light groups

[emontnemery]

Proposed change

Remove deprecated SUPPORT_WHITE_VALUE from ZHA light groups, this should not be needed as it's not referenced in ZHA lights and not supported by Zigbee.

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

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• This PR fixes or closes issue: fixes #
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[probot-home-assistant]

Hey there @dmulcahey, @Adminiuga, mind taking a look at this pull request as its been labeled with an integration (zha) you are listed as a codeowner for? Thanks!
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