Reduce concurrency of k8s tests to 1

[hsubbaraj-spiral]

Describe your changes and why you are making these changes

Reduces concurrency of K8s tests to 1 for stability reasons. Sets the timeout to 180 min to account for test time. Created a task to track the investigation of the test failures with higher concurrency.

Related issue number (if any)

Eng-2811

Loom demo (if any)

https://github.com/aqueducthq/aqueduct/actions/runs/4726107721 Run of the periodic tests.

Checklist before requesting a review

• I have created a descriptive PR title. The PR title should complete the sentence "This PR...".
• I have performed a self-review of my code.
• I have included a small demo of the changes. For the UI, this would be a screenshot or a Loom video.
• If this is a new feature, I have added unit tests and integration tests.
• I have run the integration tests locally and they are passing.
• I have run the linter script locally (See python3 scripts/run_linters.py -h for usage).
• All features on the UI continue to work correctly.
• Added one of the following CI labels:
  • run_integration_test: Runs integration tests
  • skip_integration_test: Skips integration tests (Should be used when changes are ONLY documentation/UI)

[kenxu95]

noice - just one comment about downgrading the machine power too?

[kenxu95]

Can we actually try to downgrade this to ubuntu-latest? I don't think we need anything that powerful if we're just doing concurrency 1. We might need to bump the timeout to something slightly more generous for the first run though.