Fix: One-time alarms remain enabled after ringing

[mahendra-918]

Description

When setting an alarm with repeat = never (one-time alarm), the alarm remains enabled after it rings instead of being automatically disabled. This causes the alarm to potentially ring again on subsequent days, which is not the expected behavior for a one-time alarm.

Proposed Changes

1. Consolidated the one-time alarm handling logic in alarm_ring_controller.dart:

   • Added proper handling of one-time alarm dismissal in the onClose method
   • Ensures the alarm is disabled and updated in the database when dismissed

2. Removed duplicate one-time alarm handling from splash_screen_controller.dart:

   • Removed redundant code that was trying to handle one-time alarms during app startup
   • This prevents race conditions and ensures consistent behavior

Fixes #781

Screenshots

WhatsApp.Video.2025-03-24.at.17.45.14.mp4

Checklist

• Tests have been added or updated to cover the changes
• Documentation has been updated to reflect the changes
• Code follows the established coding style guidelines
• All tests are passing

[mahendra-918]

Hi @MarkisDev can you please review this PR