Fix proper joining of the path for logs retrieved from celery workers (#26493)
Fix proper joining of the path for logs retrieved from celery workers (#26493)

The change #26377 "fixed" the way how logs were retrieved from
Celery, but it - unfortunately broke the retrieval eventually.

This PR should fix it.

Fixes: #26492
cfei18/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,apache/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,nathanielvarona/airflow,apache/airflow,cfei18/incubator-airflow