gptel-ollama: Set num_ctx to 8192

* gptel-ollama.el (gptel--request-data): Set Ollama's default
context to 8192, which is what Llama 3 supports (#330).  This is
currently not customizable, but is intended to be in the future.

Author: karthink

gptel-ollama.el

@@ -80,7 +80,8 @@ Intended for internal use only.")
            :stream ,(or (and gptel-stream gptel-use-curl
                          (gptel-backend-stream gptel-backend))
                      :json-false)))
-        options-plist)
+        ;; TODO num_ctx chosen according to #330, make customizable
+        (options-plist '(:num_ctx 8192)))
     (when gptel-temperature
       (setq options-plist
             (plist-put options-plist :temperature