chore(deps): drop @babel/core and @babel/eslint-parser

Babel was only used by test/repos.ts (consumed by the benchmark
harness and the e2e-repo suite, both excluded from CI). Replaced
the babel parser with ESLint's default espree, which handles the
ES2022 + JSX needed by the bootstrap and create-react-app
benchmark configs.

@babel/core lingers in the lockfile as a babel-jest peer, but no
longer occupies a top-level dev slot.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: amilajack