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/task/src/lib.rs

@@ -467,7 +467,7 @@ impl ShellBuilder {
 
     // `alacritty_terminal` uses this as default on Windows. See:
     // https://github.com/alacritty/alacritty/blob/0d4ab7bca43213d96ddfe40048fc0f922543c6f8/alacritty_terminal/src/tty/windows/mod.rs#L130
-    // We could use `util::retrieve_system_shell()` here, but we are running tasks here, so leave it to `powershell.exe`
+    // We could use `util::get_windows_system_shell()` here, but we are running tasks here, so leave it to `powershell.exe`
     // should be okay.
     fn system_shell() -> String {
         "powershell.exe".to_string()