Force _attr_native_value to metric in bmw_connected_drive

[rikroe]

Proposed change

The BMW API only returns metric units, even if header flags for imperial units are set (worked in a previous version of the API/MyBMW app).

This PR forces the library to always request metric units (and therefore report all values with metric units, as the API doesn't provide unit attributes anymore). The conversion to imperial units is again done by Home Assistant.

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 BMW Connected Drive reports metric data instead of miles and gallons #75223
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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• Tests have been added to verify that the new code works.

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[probot-home-assistant]

Hey there @gerard33, mind taking a look at this pull request as it has been labeled with an integration (bmw_connected_drive) you are listed as a code owner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[rikroe]

Codecov failed due to unchanged files with check annotations.

[frenck]

Thanks, @rikroe 👍