Cleanup tool registry API surface (#11637)

Fast followups to #11629 

Release Notes:

- N/A

---------

Co-authored-by: Max <max@zed.dev>

crates/assistant_tooling/src/assistant_tooling.rs

@@ -8,6 +8,6 @@ pub use attachment_registry::{
 };
 pub use project_context::ProjectContext;
 pub use tool_registry::{
-    tool_running_placeholder, LanguageModelTool, SavedToolFunctionCall, SavedToolFunctionCallState,
-    ToolFunctionCall, ToolFunctionCallState, ToolFunctionDefinition, ToolOutput, ToolRegistry,
+    LanguageModelTool, SavedToolFunctionCall, ToolFunctionCall, ToolFunctionDefinition, ToolOutput,
+    ToolRegistry,
 };