ci: up pytorch to 1.8.1

[jeffydc]

fixes #1874

Description:

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

@ydcjeff thanks for the PR! I think it is ready to merge as it is.

However, I understand now that we are still missing the correct way to trigger docker build. I think trigger it on .circleci/config.yml change would be expensive. We can think to do the following in another PR. Basically, try to make use of yml file import:

• create .circleci/docker-config.yml with

  build_docker_image_pytorch_version:
    type: string
    default: "1.8.1-cuda11.1-cudnn8"
  build_docker_image_hvd_version:
    type: string
    default: "v0.21.3"
  build_docker_image_msdp_version:
    type: string
    default: "v0.3.10"

• import it inside .circleci/config.yml :
• add .circleci/docker-config.yml to

ignite/.github/workflows/docker-build.yml

Lines 3 to 7 in ff3384b

	on:
	pull_request:
	paths:
	- docker/**
	- ".github/workflows/docker-build.yml"

and

ignite/.github/workflows/docker-publish.yml

Lines 7 to 9 in ff3384b

	paths:
	- docker/**
	- ".github/workflows/docker-publish.yml"

Probably, we also have to modify

ignite/.github/workflows/docker-build.yml

Lines 45 to 46 in ff3384b

	export PTH_VERSION=`python -c "import yaml; f=open('.circleci/config.yml'); d=yaml.safe_load(f); print(d['parameters']['build_docker_image_pytorch_version']['default'])"`
	export HVD_VERSION=`python -c "import yaml; f=open('.circleci/config.yml'); d=yaml.safe_load(f); print(d['parameters']['build_docker_image_hvd_version']['default'])"`

Let's also update MSDP to v0.3.13

[vfdev-5]

LGTM