Handle missing COPILOT_GITHUB_TOKEN gracefully for scheduled Weekly Content Update runs

[Copilot]

The Weekly Content Update workflow failed when COPILOT_GITHUB_TOKEN was not configured, due to unconditional secret validation in the agent job. This change makes scheduled runs skip the agent path when the token is absent, while keeping manual dispatch behavior unchanged.

• Root cause

  • agent job always executed and always validated COPILOT_GITHUB_TOKEN, causing hard failure on missing secret.

• Workflow behavior change

  • Added a guard so the agent job only runs when:
    • event is not schedule, or
    • secrets.COPILOT_GITHUB_TOKEN is present.
  • Result:
    • scheduled runs: skip agent job if token is missing
    • manual workflow_dispatch: still surfaces missing token misconfiguration

• Files updated

  • .github/workflows/weekly-content-update.md
  • .github/workflows/weekly-content-update.lock.yml

if: ${{ github.event_name != 'schedule' || secrets.COPILOT_GITHUB_TOKEN != '' }}