Schedule unit test coverage report

Ask for unit test coverage report.
* Currently Reviewable via github actions does coverage report for packages containing diffs per PR (json format)
* https://github.com/cockroachdb/cockroach/blob/7a79ba52b2ceef089bc33610743ca9ac39b2ad7b/.github/workflows/code-cover-gen.yml
https://github.com/cockroachdb/cockroach/blob/04392dc6aa946bb5a9158f59863dffe316ad3e10/.github/workflows/code-cover-publish.yaml
* https://docs.reviewable.io/repositories#code-coverage
* There's a teamcity job that looks like a manual trigger that generates a report, but on master it's failing, it's passing on Stan's draft branch though https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Coverage_UnitTestsCCL/20792360?hideProblemsFromDependencies=false&hideTestsFromDependencies=false&expandBuildChangesSection=true&expandBuildTestsSection=true
* https://github.com/cockroachdb/cockroach/pull/133567

https://cockroachlabs.slack.com/archives/C023S0V4YEB/p1764602026686469?thread_ts=1763630922.836859&cid=C023S0V4YEB

Jira issue: CRDB-57362

Start with .github/workflows/code-cover-gen.yml and .github/workflows/code-cover-publish.yaml to understand the existing coverage flow. Compare those workflows with the failing TeamCity unit-coverage job and PR 133567, then confirm the intended schedule, report format, and successful completion criteria.

Written by the indexing model from the issue text.