Return empty dictionary at first for attributes

[springstan]

Breaking change

Proposed change

Return empty dictionary at first for attribute properties. This makes the code easier to read because edge cases are handled first and foremost. After that the "default" behaviour is handled and then returned.

# Before
def attributes(self):
    if self._devices:
        return {"key": "value"}
    return {}

# After
def attributes(self):
    if not self._devices:
        return {}
    return {"key": "value"}

cc @balloob from #41271 (comment)

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

Example entry for configuration.yaml:

# Example configuration.yaml
n/a

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to PRs: Return attribute dict directly without temporary variable #41206 and Return attribute dict directly without temporary variable v2 #41271
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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• There is no commented out code in this PR.
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• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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[springstan]

Thanks @balloob for looking over this PR so quickly 👍