filter out commandConn.CloseRead warning log message

[crazy-max]

follow-up #2161

forgot to also filter out commandConn.CloseRead in previous PR: https://github.com/dagger/dagger-for-github/runs/6092884799?check_suite_focus=true#step:3:14

 /opt/hostedtoolcache/dagger/0.2.7/x64/dagger do test
  time="2022-04-20T10:01:52Z" level=warning msg="commandConn.CloseRead: commandconn: failed to wait: signal: terminated"
  10:01AM INF actions.test.script._write | computing
  10:01AM INF actions.test.image._dag."0"._op | computing
  10:01AM INF actions.test.script._write | completed    duration=0s
  10:01AM INF actions.test.image._dag."0"._op | completed    duration=1.7s
  10:01AM INF actions.test.image._dag."1"._exec | computing
  ...

Signed-off-by: CrazyMax crazy-max@users.noreply.github.com

[aluzzardi]

/cc @sipsma