Move continue-on-error up one level in nightly job spec

[Matt711]

Description

Follow up to #17987. I put the entry in the wrong location.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[TomAugspurger]

I think this might be at the wrong spot still. Running actionlint (or pasting the new yaml into https://rhysd.github.io/actionlint/) shows an error from continue-on-error.

❯ actionlint .github/workflows/test.yaml                                                                                                                                                                                                                                                     (base) 
.github/workflows/test.yaml:159:5: when a reusable workflow is called with "uses", "continue-on-error" is not available. only following keys are allowed: "name", "uses", "with", "secrets", "needs", "if", and "permissions" in job "wheel-tests-cudf-polars-with-rapidsmpf" [syntax-check]
    |
159 |     continue-on-error: true
    |     ^~~~~~~~~~~~~~~~~~

jobs.<job_id>.continue_on_error is valid on a normal workflow, but apparently not reusable workflows (yet, https://github.com/orgs/community/discussions/159265)

[Matt711]

I think this might be at the wrong spot still. Running actionlint (or pasting the new yaml into https://rhysd.github.io/actionlint/) shows an error from continue-on-error.

❯ actionlint .github/workflows/test.yaml                                                                                                                                                                                                                                                     (base) 
.github/workflows/test.yaml:159:5: when a reusable workflow is called with "uses", "continue-on-error" is not available. only following keys are allowed: "name", "uses", "with", "secrets", "needs", "if", and "permissions" in job "wheel-tests-cudf-polars-with-rapidsmpf" [syntax-check]
    |
159 |     continue-on-error: true
    |     ^~~~~~~~~~~~~~~~~~

jobs.<job_id>.continue_on_error is valid on a normal workflow, but apparently not reusable workflows (yet, https://github.com/orgs/community/discussions/159265)

Darn. Thanks for running [action-lint] @TomAugspurger. I wonder if we should add that it as a pre-commit hook?