Issue #3410820 by DYdave: Moved 'stale_file_threshold' config key from...
https://www.drupal.org/project/advagg/issues/3410820
Provides a way to address D10.2.0 schema validation issues:
- Moved
stale_file_threshold
config key fromsystem.performance
toadvagg.settings
.
Closes #3410820