Remove docker and user tests, related infra

[jakebailey]

These tests are currently failing because we haven't maintained these baselines.

After microsoft/typescript-error-deltas#101, the error-deltas repo and tasks will contain the full set of user/docker tests, wrapped up in a form that we actually do run and maintain.

Given the above, I think it's time to delete these runners.

Note that this is not RWC. We've already effectively committed to getting rid of RWC for more error deltas as well, but this is a different set of things.

[weswigham]

FWIW, you can also remove the DT and test262 runners, since they're even crustier - they've both only ever been invoked by hand, without persistent baseline capture. The DT runner isn't even useful on modern DT because it can't handle // $ExpectError stuff. The test262 runner only ever parsed a test262 folder in the internal repo that's not been run for 8 years. (Which we can then remove, and then maybe we can add the test262 repo to the error deltas repo, so we actually cover parsing it)

[jakebailey]

Great, I'll look into that. For DT, there are also some tasks which involve copying things around, which I assume don't work either for that reason.

I'll try in a follow-up PR if this one looks good.

[jakebailey]

Reading the test262 repo, all of the files are .case, so testing them directly is probably less than trivial. Given we haven't needed them in 8 years... maybe we skip it?

[weswigham]

.case? I think that's the exception, not the rule - I think most of the test inputs of test262 are .js, like this and all we want our test to do is basically ensure we don't crash on parsing them, right? Right.

[jakebailey]

Ah, I was in https://github.com/tc39/test262/tree/main/src. I'll take a look.