fix(changelog-check): improve devDependencies section detection in git diffs

[cryptodev-2s]

Problem

The changelog check was failing to properly detect when package.json changes were only in devDependencies because the git diff logic required both the start and end of the devDependencies section to be visible. In many cases, especially with limited diff context (-U20), the closing brace of the devDependencies section might not be included in the diff output.

Solution

• Fixed section detection logic: Use maximum context to ensure section headers are visible (-U9999) instead of (-U20)

Testing

This fix ensures that packages with only devDependency changes are properly skipped during changelog checks, preventing false positives that would require unnecessary changelog updates.

This should resolve the CI failure that occurred in this PR: MetaMask/core#6331

Impact

• ✅ Fixes false positive changelog requirements for dev-only changes

---

Note

Increase git diff context to -U9999 so package.json section headers (e.g., devDependencies) are reliably present in diffs.

• Changelog check (src/changelog-check.ts):
  • Use git diff -U9999 (max context) when analyzing package.json changes to ensure section headers like "devDependencies" are visible for accurate detection.

^{Written by Cursor Bugbot for commit 39fafdd. This will update automatically on new commits. Configure here.}

[mcmire]

Makes sense!

[mcmire]

LGTM!