security(frontend): pin js-yaml to 5.4.1+
Raise the js-yaml override from ^5.2.3 to ^5.4.1. Versions up to 5.4.0
do not count empty mappings towards maxTotalMergeKeys, so a small YAML
file can keep the CPU busy for a long time. js-yaml is a dev-only
transitive dependency of eslint and only parses our own ESLint configs.