[CT-2613] TestFastFailingDuringRun::test_fail_fast_run is flaky

[MichelleArk]

Example failing CI run: https://github.com/dbt-labs/dbt-core/actions/runs/5126607618/jobs/9236277629?pr=7739

13:43:46  Database Error in model two (models\two.sql)
13:43:46    column "failed" does not exist
13:43:46    LINE 7:     select 1 /failed
...
FAILED tests/functional/fail_fast/test_fail_fast_run.py::TestFastFailingDuringRun::test_fail_fast_run - IndexError: list index out of range

Test passes on other builds + main.

Looking closer at the failing test, I don't really see a reason why the /failed statement is necessary in "two.sql" - unless there is a dependency between the two models -- "two.sql" could run first occasionally and cause the test to fail.