**Related issue:** Resolves#41571
Changing the way delta artifacts are generated.
`changed_files_today.txt` and `changed_files_yesterday.txt` will always
look back into git history for any commits added yesterday and today.
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
## Release Notes
* **Bug Fixes**
* Improved repository synchronization to ensure local state accurately
reflects the remote main branch.
* Enhanced file change detection logic for more reliable identification
of modified files.
* Refined output file handling to maintain consistency across
synchronization cycles.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Related issue: Resolves https://github.com/fleetdm/fleet/issues/41571
It appears that there is some sort of error with shallow cloning.
```
Run echo "=== Generating OSV Artifacts for Ubuntu ==="
=== Generating OSV Artifacts for Ubuntu ===
=== OSV Repository Sync ===
Repository exists, updating with rolling window...
fatal: error processing shallow info: 4
Error: Process completed with exit code 128.
```
Since we are only keeping a limited history of the repository via cache
before re-clone, fall back to doing a regular `git pull`. This avoids
the complicated shallow cloning / Git having to reconcile the
overlapping but different shallow boundaries, which can cause "error
processing shallow info: 4".
## Testing
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Modified repository synchronization to use full fetches instead of
rolling-window shallow fetches.
* Updated sync status messaging for clarity.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Konstantin Sykulev