[v0.x] Backport CI from Master to v0.x

[barry-jin]

Description

fix issue #1529

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

Changes

• Feature1, tests, (and when applicable, API doc)
• Feature2, tests, (and when applicable, API doc)

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

cc @dmlc/gluon-nlp-team

[szha]

we probably need to move the test tasks to our own workers.

[szha]

submit-job.py: error: unrecognized arguments: --conda-env docker/py3

[barry-jin]

submit-job.py: error: unrecognized arguments: --conda-env docker/py3

For v0.x CI, should we replace current jenkins CI with github actions or keep some of the jenkins jobs and move the others to github actions. In issue #1529, the jenkins CI will pass randomly, so I try to replace current jenkins CI with github actions by backporting the cpu, gpu unittests and website build from master branch, including the submit-job.py script.

[szha]

OK. I removed the required status for the old jenkins checks.