agent: Use current shell (#28470)

Release Notes:

- agent: Replace `bash` tool with `terminal` tool which uses the current
shell

---------

Co-authored-by: Bennet <bennet@zed.dev>
Co-authored-by: Antonio <antonio@zed.dev>

crates/migrator/src/migrations.rs

@@ -37,3 +37,9 @@ pub(crate) mod m_2025_03_29 {
 
     pub(crate) use settings::SETTINGS_PATTERNS;
 }
+
+pub(crate) mod m_2025_04_15 {
+    mod settings;
+
+    pub(crate) use settings::SETTINGS_PATTERNS;
+}