Reduce log noise: demote "No pets" messages from WARNING to DEBUG

[Menelao147]

Proposed change:

This PR reduces log noise by demoting several non-critical "No pets" and similar messages from WARNING level to DEBUG level.

These warnings were being logged repeatedly for users who do not have pets registered in their Petlibro account (a common use case), cluttering the logs.

Files modified:

• date.py
• hub.py
• image.py
• number.py
• select.py
• sensor.py
• switch.py
• text.py

Closes #240

Type of change:

• New device.
• Bug fix (non-breaking change which fixes an issue).
• New feature or enhancement (non-breaking change which adds functionality).
• Documentation only.
• Other (please explain).

Checklist:

• If applicable, I have added corresponding documentation changes.
• If applicable, I have reviewed the feature / enhancement guidlines before submitting my request.
• If applicable, I have tested my code for new features & regressions on the latest version of Home Assistant.

Additional notes:

• All changes are purely logging level adjustments.
• No functional behavior is altered.
• This significantly improves the user experience for users without pets by reducing log spam while keeping the information available at debug level for troubleshooting.