Reuse conversation cache when streaming edits (#30245)

Release Notes:

- Improved latency when the agent applies edits.

crates/git_ui/src/git_panel.rs

@@ -1774,6 +1774,7 @@ impl GitPanel {
                         cache: false,
                     }],
                     tools: Vec::new(),
+                    tool_choice: None,
                     stop: Vec::new(),
                     temperature,
                 };