[ursucarina]

Tracking issue

Follow-up to #8229.

Why are the changes needed?

The discarded queue_wait_started_at field was never part of a shipped API, so its reservation is unnecessary. This addresses Haytham's review comment after #8229 merged.

What changes were proposed in this pull request?

Remove the unused field-8/name reservations and their rationale comment from ActionStatus, and regenerate the affected Go, Python, Rust, and TypeScript descriptors. Every active field keeps its existing number and type, including queued_at = 7 and worker_assigned_at = 9.

Most changed lines are generated descriptor bytes. The source change removes four lines.

How was this patch tested?

• buf format --diff --exit-code and buf lint --exclude-path flytestdlib/ pass.
• All four language targets were regenerated with the repository's pinned Buf plugins.
• go test ./gen/go/flyteidl2/workflow/... ./runs/service ./runs/testclient and go vet ./runs/service ./runs/testclient pass.
• Generated TypeScript passes npx tsc --noEmit.
• Python descriptor comparison against canonical origin/main confirms the only schema differences are the requested reservations; every active field is identical. TypeScript/Python binary and JSON round-trips preserve the timestamp fields and their exact serialized bytes, including assignment field 9. Unknown timestamps remain omitted.
• buf breaking --against '.git#ref=origin/main' --exclude-path flytestdlib/ reports exactly the two intentional RESERVED_MESSAGE_NO_DELETE findings for this requested cleanup. No breaking-check configuration was changed.

No application behavior or active protobuf fields change, so no new application tests were added. The local checks above passed; full CI is pending, including Rust crate compilation.

Check all the applicable boxes

• I updated the documentation accordingly.
• All new and existing tests passed.
• All commits are signed-off.

Related PRs

• feat(idl): add queue-scoped action listing #8229