[CT-2827] TestSingularTestsEphemeralSnowflake::test_singular_tests_ephemeral is flaky

[mikealfare]

Different status types come through the test. It's not always clear which one. The test fails when trying to assert a positive status. When it gets the correct status class (RunStatus I believe), it passes, because the value is pass. But when it gets he wrong one (TestStatus I believe), then it fails; I think this happens because the positive status on that is success, hence pass becomes fail since it's not a valid value.

[MichelleArk]

This test is also flaky in the base core implementation: TestSingularTestsEphemeral.test_singular_tests_ephemeral

https://github.com/dbt-labs/dbt-core/actions/runs/5583460196/jobs/10203801831?pr=6346

[jtcohen6]

I believe this is the test that's been flaky since the upgrade to sqlparse==0.4.4. It only fails on Ubuntu. This is what motivated us to pin sqlparse<0.4.4 previously:

• [CT-2432] [CT-2431] [Bug] sqlparse patch version 0.4.4 breaks ephemeral models #7396

It was also reported in the wild by a handful of users:

• [CT-2539] [Bug] CTE SQL Injection in Postgres #7521
• [CT-2561] [Bug] dbt model referencing an ephemeral model results in broken compiled SQL code #7595

We weren't able to identify root cause, nor were we able to rip out sqlparse and replace it with something more naive.

[aosingh]

As a temporary workaround for all testcases to pass in our Github Actions CI pipeline, I reinstall sqlparse==0.4.3

[jtcohen6]

Pretty sure this should be fixed by #8215