Update Archiving Logic to Use Dynamic Release Data

The issue archiving logic in #getIssuePath() is currently tied to a static configuration. It needs to be refactored to use the dynamic list of releases fetched from GitHub at the start of the sync process.

Acceptance Criteria

1. The #getIssuePath() method in SyncService.mjs is refactored.
2. When determining the version for a closed issue, the method no longer references a static config.
3. Instead, it iterates over the this.releases array (populated by #fetchAndCacheReleases()).
4. It correctly identifies the target version by finding the first release in the sorted list whose publishedAt date is after the issue's closedAt date.
5. The logic for handling issues with an explicit milestone remains as a priority.

Benefits

• Completes the transition to a fully dynamic, date-based synchronization system.
• Ensures that closed issues are always archived into the correct, most recent release folder without manual intervention.
• Makes the archiving logic resilient to changes in the project's release cadence.