feat(ci): add self hosted runner for long tests

[gustavovalverde]

Motivation

We've been creating several jobs to workaround GitHub's 6 hour time limit for hosted runners, but this approach has been hard to maintain, created several edge cases (issues) with SSH connections and made the workflow way too verbose.

Closes: #5572
Depends-On: #7507

Specifications

• Uses self-hosted runners, which were deployed using ACR: https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners-with-actions-runner-controller

Complex Code or Requirements

• We need to confirm the regex in the test-result job works for all tests

Solution

• Use self-hosted runner instead of GitHub Hosted runner
• Remove all intermediate jobs which were meant to extend the run of the test over the 6 hours limit
• Move the startup validation and test run steps into a single job
• Combine setup and launch jobs in a single job (2 jobs total)

Review

• This should execute over 6 hours for a Zebra and LWD sync
• The sync should end successfully

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

Follow Up Work

[gustavovalverde]

Running test: https://github.com/ZcashFoundation/zebra/actions/runs/6145420016

[teor2345]

This looks great, thank you so much for simplifying this. I have a bunch of questions, but I think the most important one is about the long test setting and timeouts.

Everything else should still work the way it is, or if it doesn't work, we'll pick it up in the tests.

Would you mind delaying merging this PR until after #7507 merges?
@oxarbitrage and I are working on a complicated cached state rebuild, which needs to finish before the scheduled jobs run on Friday. So I'd like to get it done first.
#7507 (comment)

(And if you have any ideas for making that easier, feel free to comment on that PR, or open a ticket to make rebuilds work better.)

[teor2345]

Thanks for this, and for the quick changes! I have just approved the dependent PR, so this one will hopefully merge before tomorrow.

(I love deleting complicated code that isn't needed any more.)