Actually run the eval and fix a hang when retrieving outline (#28547)

Release Notes:

- Fixed a regression that caused the agent to hang sometimes.

---------

Co-authored-by: Thomas Mickley-Doyle <tmickleydoyle@gmail.com>
Co-authored-by: Nathan Sobo <nathan@zed.dev>
Co-authored-by: Michael Sloan <mgsloan@gmail.com>

crates/agent/Cargo.toml

@@ -19,7 +19,6 @@ test-support = [
 ]
 
 [dependencies]
-agent_rules.workspace = true
 anyhow.workspace = true
 assistant_context_editor.workspace = true
 assistant_settings.workspace = true
@@ -81,6 +80,7 @@ terminal.workspace = true
 terminal_view.workspace = true
 text.workspace = true
 theme.workspace = true
+thiserror.workspace = true
 time.workspace = true
 time_format.workspace = true
 ui.workspace = true