It expired on Mar 17, 2021, causing tests to fail:
=== RUN TestConfigClientExclusiveRootPools
config_test.go:595: Unable to verify certificate 1: x509: certificate has expired or is not yet valid: current time 2021-07-21T14:20:01Z is after 2021-03-17T16:40:46Z
to fix the failures on https://github.com/docker/go-connections/pull/84
It expired on Mar 17, 2021, causing tests to fail: