[Bug]: UT coverage setup action times out during cold Go/JDK provisioning

## Summary

PR #28272 at exact head `075485fdf8113b36bdd39c8ce39840efdea01f46` failed before the UT coverage command started because the reusable coverage action exhausted its setup-phase time budget.

- Source PR: https://github.com/matrixorigin/matrixone/pull/28272
- Workflow run attempt 1: https://github.com/matrixorigin/matrixone/actions/runs/34493451556
- UT coverage producer: https://github.com/matrixorigin/matrixone/actions/runs/34493451556/job/102925963574
- Derived Coverage failure: https://github.com/matrixorigin/matrixone/actions/runs/34493451556/job/102942693428
- Derived CI Required failure: https://github.com/matrixorigin/matrixone/actions/runs/34493451556/job/102945363241
- Reusable workflow revision: `matrixorigin/CI@2ab1af3a85ca3c4e4eab7483201aca3e1913dd99`
- Runner: `amd64-mo-guangzhou-2xlarge16-jvhxs-runner-v79qj`

## Actual behavior

The setup phase began at 15:07:47 UTC. `actions/setup-go@v5` completed successfully only after 548.247 seconds. The following `actions/setup-java@v4` resolved and downloaded JDK 8, began extracting it, and then the enclosing action reached its timeout at 15:17:47 UTC:

```text
##[end-action ... setup-go;outcome=success;duration_ms=548247]
##[start-action display=Set up JDK 8 for x64]
Downloading Java 8.0.504+1 ...
Extracting Java archive...
##[error]The action has timed out.
```

No MatrixOne build, test, coverage-profile, assertion, panic, race, or changed-code coverage verdict ran. The producer reported `external_timeout_or_cancellation`.

The derived Coverage job received `prerequisites_ready: false` and failed with:

```text
coverage merge blocked: a required producer did not publish a complete coverage profile; no coverage verdict was calculated
```

CI Required then failed only because `matrixone-ut-coverage` and the coverage merge failed.

## Expected behavior

Toolchain setup should either use a warm/cached runtime or have a budget that allows cold setup to complete, so transient runner or network latency cannot consume the entire coverage action before tests begin.

## Attribution

PR #28272 does not modify MatrixOne CI workflow/orchestration files, dependency manifests, or toolchain setup. In the same exact-head run, regular Ubuntu UT, shared build, SCA, and both selected BVT jobs passed. The failure is in the protected reusable CI workflow/toolchain provisioning boundary, not MatrixOne product code.

## Steps to reproduce

1. Run MatrixOne ALL CI with a coverage runner that lacks the requested Go/JDK artifacts.
2. Let setup-go consume most of the enclosing setup action budget.
3. Observe setup-java get cancelled at the action timeout before the coverage command starts.
4. Observe the Coverage and CI Required jobs fail transitively because no UT profile exists.