Fix stale tool-call atom with Copilot encrypted IDs

Copilot API returns different encrypted item IDs in streaming events
vs response.completed output. The selective dissoc only removed the
output ID, leaving the streaming ID (with arguments) in the atom.
Replace with a full reset before the recursive request.

🤖 Generated with [eca](https://eca.dev)

Co-Authored-By: eca <git@eca.dev>

Author: ericdallo

src/eca/llm_providers/openai.clj

@@ -277,8 +277,7 @@
                                      :input-cache-read-tokens input-cache-read-tokens}))
                 (if (seq tool-calls)
                   (when-let [{:keys [new-messages tools]} (on-tools-called tool-calls)]
-                    (doseq [tool-call tool-calls]
-                      (swap! tool-call-by-item-id* dissoc (:item-id tool-call)))
+                    (reset! tool-call-by-item-id* {})
                     (base-responses-request!
                      {:rid (llm-util/gen-rid)
                       :body (assoc body