settings: Migration for fixing duplicated agent keys (#30237)

As a byproduct, this fixes bug where it's impossible to change Agent
profile

Closes #30000 

Release Notes:

- N/A

crates/migrator/src/patterns.rs

@@ -8,6 +8,6 @@ pub(crate) use keymap::{
 
 pub(crate) use settings::{
     SETTINGS_ASSISTANT_PATTERN, SETTINGS_ASSISTANT_TOOLS_PATTERN,
-    SETTINGS_EDIT_PREDICTIONS_ASSISTANT_PATTERN, SETTINGS_LANGUAGES_PATTERN,
-    SETTINGS_NESTED_KEY_VALUE_PATTERN, SETTINGS_ROOT_KEY_VALUE_PATTERN,
+    SETTINGS_DUPLICATED_AGENT_PATTERN, SETTINGS_EDIT_PREDICTIONS_ASSISTANT_PATTERN,
+    SETTINGS_LANGUAGES_PATTERN, SETTINGS_NESTED_KEY_VALUE_PATTERN, SETTINGS_ROOT_KEY_VALUE_PATTERN,
 };