Remove needs: wheel-build-cudf. (#14427)

This PR fixes a nightly test failure due to an extraneous `needs:` entry in `test.yaml`.

```
Invalid workflow file: .github/workflows/test.yaml#L100
The workflow is not valid. .github/workflows/test.yaml (Line: 100, Col: 12): Job 'unit-tests-cudf-pandas' depends on unknown job 'wheel-build-cudf'.
```

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - Ray Douglass (https://github.com/raydouglass)

URL: #14427

.github/workflows/test.yaml

@@ -97,7 +97,6 @@ jobs:
       sha: ${{ inputs.sha }}
       script: ci/test_wheel_dask_cudf.sh
   unit-tests-cudf-pandas:
-    needs: wheel-build-cudf
     secrets: inherit
     uses: rapidsai/shared-workflows/.github/workflows/[email protected]
     with: