From Drupal 10.1.x allowed_formats setting was added to Formatted text field types
see https://www.drupal.org/node/3318572 →
"Key / Value (long)" field type extends "Text (formatted, long)" core field type, so it will have allowed_formats setting too, but currently it is not described in field.field_settings.key_value_long config schema, so we got Missing schema error from config inspector
Also we're missing definition for description in config schemas for field.value.key_value and field.value.key_value_long.
Update field.field_settings.key_value_long schema to inherit field.field_settings.text_long schema from core
Add desctiption to field.value.key_value and field.value.key_value_long schemas
Postponed
1.0
Code
The same fix has been applied under 📌 Automated Drupal 11 compatibility fixes for key_value_field Needs review in commit ec7c1e5c. Leaving the ticket still open to let module maintainers grant credit to @sorlov → when marking as Fixed.