Changes

chore(tidb): remove periodic integration pipeline (#4466)

## Summary
- redo the stale removal from #4059 on current `main`
- delete the TiDB periodic integration Jenkins job, pipeline, and pod
template
- remove the matching prow periodic job definition from
`prow-jobs/pingcap/tidb/latest-periodics.yaml`

## Testing
- `rg -n
"pingcap/tidb/periodics_integration_test|periodics_integration_test"
prow-jobs jobs pipelines docs .ci`
- `PATH="$(mktemp -d)":$PATH` with temporary `yq` binary to run
`.ci/update-prow-job-kustomization.sh`
- `git diff --check`

```release-note
none
```
 (commit: 4adcca5)