[v3.5] Update OpenTelemetry to v1.0+

[dashpole]

Part of #12460.

Given the release delays for v3.6, I'd like to propose updating the OpenTelemetry version used in etcd release-3.5 to v1.0+. A quick go get -u shows that it would also require updating github.com/stretchr/testify from v1.7.0 to v1.7.1. That would help unblock using 1.0+ in kubernetes, which would unblock users that have a dependency on the kubernetes client as well.

cc @logicalhan @damemi @CatherineF-dev @dgrisonnet @serathius @sallyom

[ahrtr]

It's already in my to do list. Will get it resolved.

[ahrtr]

cc @spzala @nikhita

[ahrtr]

Fixed by #14312