chore(ci): clean up disabled workflow stale conditions

[Zena-park]

Context

Follow-up from PR #52 code review.

Task

• .github/workflows/pr-main_l2_tdx_build.yaml:24 — Workflow is disabled (on: pull_request removed) but job if still references github.event.pull_request.labels. Clean up or remove the stale conditional (review)

Related

• PR feat(platform): Explore page redesign with social features and announcements #52