Fix displaying useless Auto mode in Google Home thermostat

[KipK]

Removed useless Auto mode ( HeatCool is Jeedom Auto mode ) . Former Auto mode seems to have disappeared from google api.

Remove useless Mode trait for Thermostat, thermostat modes are handled by TemperatureSetting trait.

Thread reference :
https://community.jeedom.com/t/bug-report-thermostats-attribut-auto-toujours-publie-sur-gsh-meme-si-non-renseigne/132801

Related issues/external references

Auto mode was useless, always displayed, and misleading.

Types of changes

• Bug fix (non-breaking change which fixes)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement

PR checklist

• [X ] I have checked there is no other PR open for the same change.
• [X ] I have read the Contribution Guidelines.
• [X ] I grant the project the right to include and distribute the code under the GNU.
• [X ] I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [X ] [Required for new sniffs] I have added MD documentation for the sniff.