feat: add gitleaks for woodpecker

---

when:

  - event: "push"

    branch: "main"

  - event: "manual"

steps:

  - name: "gitleaks"

    # renovate: datasource=github-releases depName=gitleaks/gitleaks

    image: "cr.simoncor.net/ghcr/gitleaks/gitleaks:v8.30.1"

    commands:

      - "gitleaks detect --source . --verbose --redact"