fix: make sure validator.ts uses relative paths for imports (#82761)
Previously, `.next/types/validator.ts` looked like this after a build:
```typescript
// Validate /Users/you/code/next.js/test/e2e/app-dir/typed-routes/app/dashboard/@team/page.tsx
{
const handler = {} as typeof import("/Users/you/code/next.js/test/e2e/app-dir/typed-routes/app/dashboard/@team/page.js")
handler satisfies AppPageConfig<"/dashboard">
}
```
Now, it looks like this:
```typescript
// Validate ../../app/dashboard/@team/page.tsx
{
const handler = {} as typeof import("../../app/dashboard/@team/page.js")
handler satisfies AppPageConfig<"/dashboard">
}
```
This can be important for security reasons.