fix:ollama text embedding 500 error (#8252)

api/core/model_runtime/model_providers/ollama/text_embedding/text_embedding.py

                 inputs.append(text)
 
         # Prepare the payload for the request
-        payload = {"input": inputs, "model": model, "options": {"use_mmap": "true"}}
+        payload = {"input": inputs, "model": model, "options": {"use_mmap": True}}
 
         # Make the request to the Ollama API
         response = requests.post(endpoint_url, headers=headers, data=json.dumps(payload), timeout=(10, 300))