请帮我弄清楚。代码工作到上周五没有问题。今天经过几次启动，我一直得到错误：
google.API_core.exceptions.RetryError：Deadline of 600.0s exceeded while calling target function，last exception：HTTPSConnectionPool（host ='oauth2.googleapis.com'，port=443）：Max retries exceeded with url：/token（Caused by SSLError（SSLCertVerificationError（1，'[SSL：CERTIFICATE_VERIFY_FAILITY] certificate verify failed：unable to get local issuer certificate（_ssl.c：1007'）））
我既不能下载也不能发送数据到Big Query。

import pandas as pd
    from dotenv import load_dotenv
    from google.cloud import bigquery
    load_dotenv('.env')
    
    
    def create_bq_conn():
        CREDS_BIG_QUERY = r'C:\Users\path_to_file\some_creds.json'
        bclient = bigquery.Client.from_service_account_json(json_credentials_path=CREDS_BIG_QUERY)
        return bclient
    
    def result_df():
        query_job = create_bq_conn().query('SELECT * FROM `table`') 
        bqdf = query_job.to_dataframe()
        return bqdf
    
    result_df()

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