fix: relative navigation from index/pathless routes

[brophdawg11]

Continuation of #8697

Closes #8350

[brophdawg11]

@ryanflorence Quick double check here that this double ../.. would be the expected relative path to the /about route?

[ryanflorence]

<Route path="about" />
<Route path="home" element={<Outlet />}>
  <Route element={<Outlet />}>
    <Route element={<Outlet />}>
      <Route element={<Outlet />}>
        <Route
          path="page"
          element={<Navigate to="../../about" />}
        />

Should ignore all the pathless routes, so essentially we're talking about this:

<Route path="about" />
<Route path="home" element={<Outlet />}>
  <Route
    path="page"
    element={<Navigate to="../../about" />}
  />

• .. goes up to /home route
• .. x2 goes up to /
• about goes to /about

So yeah, that sounds right!