Decrease min_columns to 8 for hui-statistics-graph-card

[MindFreeze]

Proposed change

Some users have tiny charts on their dashboards. This won't make everyone happy but it would improve it for 1-2 users, while we figure out a way forward.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: Statistics graph Card layout bloated after  #23576
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

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

If user exposed functionality or configuration variables are added/changed:

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