This fixes a bug when unstable_defaultShouldRevalidate={false} is used and a matched route does not export a shouldRevalidate function. The current code skips counting the route as a route to opt out when determining when to set the _routes query param.

I wrote a test with 3 routes, all with their own loaders and no shouldRevalidate functions.

app/root.tsx
app/parent.tsx
app/parent.a.tsx

When on the /parent route, i'm clicking a link with unstable_defaultShouldRevalidate={false} to navigate to /parent/a. This should trigger a data call for only app/parent.a.tsx's loader. However, the data call that's executed does not have the _routes query param, so all loaders are revalidated.

This PR makes it so that the data call is only to fetch app/parent.a.tsx's loader data.