Minor[CI]: publish-test-results not marked as failed

[milesgranger]

Change the publish unit test result action to not report itself as failed if other tests in CI have failed, only on errors.

Rationale:
PRs like #10824 get the ugly ❌ when any tests fail b/c the action itself reports itself as failed when any tests in the CI has failed.

However, "nothing" in the PR has failed, only tests for dask-expr which are expected and thus marked green on CI.
https://github.com/dask/dask/actions/runs/7567879416/job/20607928150?pr=10824#step:8:28559

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

     15 files  ±0       15 suites  ±0   3h 29m 23s ⏱️ - 9m 31s
 12 911 tests ±0   11 958 ✅  - 1     929 💤 ±0  24 ❌ +1 
159 969 runs  ±0  143 379 ✅ +3  16 566 💤  - 4  24 ❌ +1 

For more details on these failures, see this check.

Results for commit 33afda7. ± Comparison against base commit 6b76a5a.

[milesgranger]

Note the changes aren't reflected until in main.
I've tested this on my fork here: milesgranger#5 (merged this PR in my fork w/ a test PR)

[phofl]

thx, lets try it