ci: add workspace PVC overrides for remaining migrated GCP Jenkins jobs (#4510)
## Summary - add explicit `workspace-volume` ephemeral `volumeClaimTemplate` overrides to the remaining migrated GCP Jenkins pod templates - keep the workspace override in pod YAML instead of pipeline DSL - complete phase-2 after `#4509` validated the rollout pattern on a single job
## Scope This PR covers the remaining `agent=jenkins && labels.master=1` declarative jobs that still relied on the Jenkins kubernetes plugin default workspace `emptyDir`.
## Sizing rule - when a pod already had an ephemeral PVC pattern, the new `workspace-volume` reuses that pod's existing PVC sizing signal - otherwise the workspace PVC defaults to `150Gi` with `storageClassName: hyperdisk-rwo`
Resulting distribution in this PR: - `150Gi`: 124 pod templates - `200Gi`: 5 pod templates - `300Gi`: 1 pod template
## Validation - parsed all 130 changed pod YAML files locally - verified every changed file now contains exactly one `spec.volumes[].name=workspace-volume` - verified every added workspace PVC resolves to `storageClassName=hyperdisk-rwo` - verified no remaining target pod template in the rollout scope is missing the workspace PVC override (commit: 86b6bde)