Check that there is a depreciation date before formatting

[snipe]

This just checks that the depreciation_date() is not null before trying to format it

[what-the-diff]

PR Summary

• Modification in 'ReportsController.php' File
  The code responsible for managing reports was updated. Previously, it was assuming that all assets should have a depreciation date, which may not always be the case. The new change ensures the code now checks if an asset actually has a depreciation date before trying to format it. This enhancement increases the robustness and reliable performance of our asset reporting feature by preventing potential errors.