Update docker client library to 20.10

[sparrc]

Summary

Ran the following go module update commands:

go get github.com/docker/[email protected]
go mod tidy
go mod vendor

The microsoft library was updated to fix a build issue in the latest docker library with the version of hcsshim we were using. See commit message:

this is to fix a dependency in the windows docker library which depends
on this file and it's Build() function:
https://github.com/microsoft/hcsshim/blob/v0.8.15/osversion/osversion_windows.go

without bumping this we get windows build failures like this:

+ go build -ldflags ' -s' -o out/amazon-ecs-agent.exe ./agent/
Error: agent/vendor/github.com/docker/docker/pkg/system/lcow.go:21:31: undefined: osversion.Build
make: *** [Makefile:60: xplatform-build] Error 2

Testing

verified long functional tests ran on AL2 platform

manually verified agent builds, runs, and runs tasks on an AMI with an older docker version (19.03.13)

Description for the changelog

Enhancement: update docker client library to latest

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.