Deprecate KFP v1 SDK support

[nikelite]

New TFX version discontinues KFP v1 SDK support.

[briron]

Thanks for the work! However, some tests failed or were canceled. Do you have any idea why?

[briron]

It is probably not related to this PR, but the test tests (3.10, not e2e, DEFAULT) is failing in this PR because of KEYERROR, and _BASE_CONTAINER_IMAGE = os.environ['KFP_E2E_BASE_CONTAINER_IMAGE'] seems to be a culprint of the failure.

[nikelite]

I think we should update some CI settings and/or some test utility files. Since py_test collects non-e2e tests at runtime, the unit tests are complaining that there are no valid environments.

cc: @peytondmurray

[peytondmurray]

Tagging @smokestacklightnin and @aktech for input

[peytondmurray]

Hmm, I think these environment variables are for telling the tests what external docker containers are running so that various external services can be called. I don't think we should be collecting these tests, as we are not currently running any docker containers during the testing CI jobs. Let me make a PR...

[peytondmurray]

@nikelite Normally I'd make a PR against your feature branch, but you're merging your master into the upstream master, so I've just made a PR against your master: nikelite#1

If you merge that, the tests should pass here. The exception will be with the NIGHTLY tests; our dependencies are in a weird state where their allowed versions are not precisely enough defined for pip's dependency solver to quickly find a solution, nor are they loosely defined enough for a solution to be easily found. As a result the NIGHTLY tests spend a huge amount of time downloading tons of versions of the various dependencies to try to find a solution. This is something we should make an issue for because currently it blocks folks from using NIGHTLY.