Turbopack: Allow overriding tsconfig path via next-config (#77563)
This:
- Adds a test asserting the user can override the tsconfig path via the
next-config. This is already supported with Next.js and Webpack.
- Implements the necessary code to pass the test and implement support
with Turbopack.
Test Plan: `pnpm test-dev test/e2e/tsconfig-path/index.test.ts && pnpm
test-dev-turbo test/e2e/tsconfig-path/index.test.ts`
Closes PACK-4215