Merge pull request aws#600 from Dylan-AWS/master

Update runtime versions for ubuntu and amazonlinux2 x86 images

Release standard:6.0 and amazonlinux2-x86_64-standard:4.0 (aws#543)

* Release standard:6.0 and amazonlinux2-x86_64-standard:4.0

Update linux dockerfiles for standard:5.0,standard:4.0,amazonlinux2:3…

….0 (aws#535)

* Update linux dockerfiles for standard:5.0,standard:4.0,amazonlinux2:3.0

Update Dockerfiles

Upgrade Docker to 20.10.9 and pin python setuptools to 57.4.0

Update SSM agent versions

Merge pull request aws#453 from rasarora/master

Update Linux Images

Merge pull request aws#435 from xgnl/master

Update Python runtime versions

add back license notice

Merge pull request aws#384 from aws/dockerfile-sync

Golang version upgrade and SSM agent update.