fix(ci): skip PR-body lint on synchronize (refs #3030)

[apmantza]

Summary

Refs #3030 on exact base 32f4d58d0d870a16e29c6b78586cb74d7197dd6f.
The branch head is f5e8a365d27865da217ec363eb448d85605b9bbe. The advisory
pr-body-lint job now skips ordinary pull-request synchronize events. It
still runs for opened, reopened, and edited events, and
scripts/check-pr-body.mjs and advisory status are unchanged.

Tests

• Pre-edit base contract: npm run build then
  node_modules/.bin/vitest run tests/config/advisory-tool-workflow.test.ts --configLoader runner
  passed 13 tests.
• Red-first regression on the original body predicate: 1 failed, 13 passed;
  #3030 PR body lint event coverage reported expected true to be false.
• Fixed targeted contract: 15 passed.
• Compile-valid mutation removing the synchronize exclusion: 2 failed, 13
  passed; the ci: run PR-body validation only on body-relevant events #3030 synchronize and exclusive-exclusion assertions both
  reported the expected red result.
• Correction round targeted contract: 15 passed; full post-build suite:
  1,682 passed, 6 skipped across 109 files.
• npm run build: passed.
• npm run fmt:check: passed (1,831 files).
• git diff --check: passed.
• actionlint .github/workflows/lint.yml: unavailable; actionlint is not
  installed in this environment. CI must confirm the workflow actionlint lane.
• Grammar prefetch emitted the repository's existing offline/CDN-unreachable
  warnings; the targeted workflow test remained network-independent and passed.

Blast radius

Changed symbols: the pr-body-lint job-level if and its real-YAML contract
test. The workflow trigger remains pull_request types
opened,synchronize,reopened,edited; push, repository_dispatch, and all
other job predicates remain unchanged. The job population sweep found:
validate-merge-train-dispatch, actionlint, pr-title-lint, pr-body-lint,
oxfmt, knip, markdownlint, record-post-merge-validation, vale,
oxlint-advisory, jscpd, complexity, strictness, yamllint, typos,
and taplo. Only pr-body-lint changed.

Class sweep

Swept all jobs and all pull-request event predicates in .github/workflows/lint.yml.
Verdict: stay distributed; this is a job-local event policy and no shared
helper or additional event seam is warranted. pr-title-lint, actionlint,
oxfmt, dispatch validation, and every other lint job retain their prior event
coverage. No language or runtime surface is involved.

Observability

No new failure path or telemetry is added. The existing advisory check remains
visible on its retained events; synchronize runs no longer create the body
check. The regression observes the parsed real workflow text.

Test assessment

tests/config/advisory-tool-workflow.test.ts uniquely pins the workflow's
advisory and policy-job contracts. Its existing #2714 assertion was narrowed
only enough to permit the intentional body-only event predicate while still
requiring dependabot exclusion on both policy jobs.

Finding disposition

• ci: run PR-body validation only on body-relevant events #3030: fixed.
• Issue text lookup: gh issue view 3030 was unavailable because this
  environment has no GitHub CLI authentication; the requested repository
  contract and exact-base behavior were verified locally.

Preflight

npm run preflight completed with no emitted table or diagnostic output. The
runner did not surface the shell's exit-code line, so the preflight result is
unverifiable here and must be confirmed by CI.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud