fix #27: correct sensor throttling for ESPHome 2025.8.0

[drothenberger]

ESPHome 2025.8.0 has removed the throttle property in the LD2412 and ld2450 stanzas. Replace those with throttle filter settings on the sensors.

Version: 2025.8.20.1

What does this implement/fix?

Fixes #27. Replace the global "throttle" setting with per-sensor throttle filters.

Types of changes

• Bugfix (fixed change that fixes an issue)
• New feature (thanks!)
• Breaking change (repair/feature that breaks existing functionality)
• Dependency Update - Does not publish
• Other - Does not publish
• Website of github readme file update - Does not publish
• Github workflows - Does not publish

Checklist / Checklijst:

• The code change has been tested and works locally
• The code change has not yet been tested

If user-visible functionality or configuration variables are added/modified:

• Added/updated documentation for the web page

[TrevorSchirmer]

Thank you very much for the contribution!