agent: Migrate tool names in settings (#29168)

Release Notes:

- agent: Add migration to rename `find_replace_file` tool to
`edit_file`, and `regex_search` to `grep`.

crates/migrator/src/migrations.rs

@@ -45,3 +45,9 @@ pub(crate) mod m_2025_04_15 {
     pub(crate) use keymap::KEYMAP_PATTERNS;
     pub(crate) use settings::SETTINGS_PATTERNS;
 }
+
+pub(crate) mod m_2025_04_21 {
+    mod settings;
+
+    pub(crate) use settings::SETTINGS_PATTERNS;
+}