1.40.6

Various fixes & improvements

• Fix compatibility with greenlet/gevent (#2756) by @sentrivana
• Fix query source relative filepath (#2717) by @gggritso
• Support clickhouse-driver==0.2.7 (#2752) by @sentrivana
• Bump checkouts/data-schemas from 6121fd3 to eb941c2 (#2747) by @dependabot