chore: remove unused @babel/runtime-corejs3 devDependency

[Garbee]

What

Removes the @babel/runtime-corejs3 entry from devDependencies in package.json, along with its three corresponding entries in pnpm-lock.yaml (the root importer record plus the package and snapshot blocks).

Nothing else changes. core-js, core-js-pure, and their allowBuilds: false entries in pnpm-workspace.yaml are unrelated and stay put.

Why

This resolves Dependabot PR #5194, which proposed bumping @babel/runtime-corejs3 from 7.29.7 to 8.0.0 — a major release whose headline breaking change is "Remove corejs exports for @babel/runtime-corejs3". Rather than absorb a major bump, investigation showed the package is entirely unused:

• The only occurrence outside the lockfile was its own declaration in package.json.
• @babel/runtime-corejs3 is only ever consumed via @babel/plugin-transform-runtime. That plugin is not installed and appears nowhere in the repository.
• .babelrc — the only Babel config the build reads, via build/run-build/babel-transform.mjs → full-build.mjs — uses @babel/preset-env with no useBuiltIns or corejs options, plus @babel/plugin-transform-object-rest-spread. Nothing pulls the runtime helpers in.
• Runtime polyfills come from core-js-pure directly in lib/core/imports/polyfills.js and lib/core/imports/index.js, which are untouched.
• doc/examples/jest_react/ has its own isolated package.json and never referenced it.
• pnpm-lock.yaml listed it only as a root importer devDependency; no other package depended on it.

It arrived in a bulk dependency update in d01532c (#3539, 2022) and has never been imported.

Note on the lockfile diff

The lockfile edit is deliberately scoped to the three affected blocks rather than produced by a full pnpm install regeneration.

package.json pins "chromedriver": "latest". Because that is a floating spec, any manifest edit causes pnpm install to re-resolve it — a full regeneration here also bumped chromedriver 151.0.2 → 151.0.5 and dragged along axios, adm-zip, and form-data, burying a 12-line removal in ~57 lines of unrelated churn. The scoped lockfile is verified consistent: pnpm install --frozen-lockfile accepts it and correctly prunes the package.

That floating pin will keep polluting the diff of every future dependency change; worth addressing separately.

Acceptance criteria

• @babel/runtime-corejs3 absent from package.json devDependencies
• All three pnpm-lock.yaml blocks (importer, packages:, snapshots:) removed, with no residual reference
• pnpm install --frozen-lockfile succeeds and proposes no lockfile drift
• Built axe.js / axe.min.js byte-identical to a develop build
• pnpm test, pnpm run fmt:check, and pnpm run eslint all clean

Related

Supersedes Dependabot PR #5194.

[Copilot]

Pull request overview

This PR removes the unused @babel/runtime-corejs3 devDependency from the root package manifest and prunes the corresponding entries from the pnpm lockfile, avoiding an unnecessary major-version upgrade path and keeping the dependency graph minimal.

Changes:

• Removed @babel/runtime-corejs3 from devDependencies in package.json.
• Removed the corresponding root importer, package, and snapshot records from pnpm-lock.yaml.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
package.json	Drops unused @babel/runtime-corejs3 from root devDependencies.
pnpm-lock.yaml	Prunes the associated lockfile entries to match the manifest removal.

Files not reviewed (1)

• pnpm-lock.yaml: Generated file

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.