Changes

ci(tidb): switch ddlv1 unit test to bazel test (#4586)

### What changed

- Switch latest ddlv1 unit test jobs from `make
bazel_coverage_test_ddlargsv1` to
`./build/jenkins_unit_test_ddlargsv1.sh`.

### Why

`build/jenkins_unit_test_ddlargsv1.sh` in TiDB now runs `make
bazel_ci_test_ddlargsv1`, which uses `bazel test` instead of `bazel
coverage`.

The ddlv1 unit test jobs have been flaky with Bazel test timeouts under
coverage mode. Switching to the TiDB-provided ddlargsv1 unit test script
aligns the job with the new TiDB-side execution path and avoids coverage
instrumentation overhead.

### Repaly Test Passed
-
https://prow.tidb.net/jenkins/job/pingcap/job/tidb/job/merged_unit_test_ddlv1/191/
-
https://prow.tidb.net/jenkins/job/pingcap/job/tidb/job/pull_unit_test_ddlv1/1153/

Signed-off-by: lyb <yebin.li@pingcap.com>
 (commit: 21aee7e)