[IMPROVEMENT] Improve the Send Reminder Notifications 2 Days Before Book Due Date Feature

### Is this feature already requested?

- [X] I have checked "open" and "closed" issues, and this is not a duplicate.

### Problem or Missing Functionality

The system currently sends reminder notifications 2 days before the book's due date by querying the database on daily basis to check for due books. This process may involve daily database queries, which can lead to performance inefficiencies.

# **Improvement Request**
1. **Optimize Database Queries**:
- Reduce the number of queries being made to the database while fetching due books for sending reminders.

2. **Performance Enhancement**:
- Analyze the existing workflow to identify potential bottlenecks.
- Implement improvements that reduce the overall time taken to send reminders and the resource usage.

3. **Documentation**:
- Document the optimized solution clearly for future developers.
- Include details about the new logic, optimized query flow, and how it impacts performance.

### **Expected Outcome**
- Fewer database queries.
- Improved system performance, especially around the time reminders are sent.
- Well-documented changes for easier maintenance.