The `tsconfig` files were unified with a common configuration in https://github.com/vercel/vercel/pull/10667 including disabling source maps. The source maps greatly increase the distribution size, but they are invaluable when the tests run, so this PR enables source maps for tests including adding a `tsconfig.json` where absent. Linear: https://linear.app/vercel/issue/ZERO-364/enable-sourcemaps-in-all-testtsconfigjson-files
@vercel/error-utils
While working on #8742 i found some useful error checking code buried in the CLI. This PR adds a new private package `@vercel/errors` that moves those helpful utilities into its own package so it can be used throughout the monorepo.