chore(eslint): ignore packages dir (#4963)

Summary

build-dist generates a packages/lockfile/index.js file that eslint should ignore.

Test plan

Run yarn build-dist, then yarn lint, and expect not to see a ton of errors.

Author: rhendric

.eslintignore

@@ -9,3 +9,4 @@ scripts
 updates
 artifacts
 dist
+packages