Match error on rendering error pages ErrorHTML

### Environment

* Elixir version (elixir -v): 1.17.2
* Phoenix version (mix deps): 1.7.21
* Phoenix LiveView version (mix deps): 1.0.10
* Beacon version (mix deps): 0.5.1
* Operating system: OSX 15.4
* Browsers on which you attempted to reproduce this bug (the more the merrier): Chrome

### Actual behavior

Site will not render configured error page on beacon_live_admin and raise a Match error such as:

```
[warning] failed to render error page for 404.html, fallbacking to default Phoenix error page

Got:

%MatchError{term: {Beacon.Web.PageLive, [action: :path, router: MyAppWeb.Router], %{extra: %{session: {Beacon.Router, :session, [:home, %{}]}, root_layout: {Beacon.Web.Layouts, :runtime}, on_mount: []}, name: :beacon_home}}}
```

### Expected behavior

Error pages should be rendered without any raised errors

Start by reproducing a 404 on beacon_live_admin with the listed Elixir, Phoenix, and LiveView versions, then inspect the MatchError tuple involving Beacon.Web.PageLive and Beacon.Web.Layouts. Done means configured error pages render without raising or falling back to the default Phoenix error page.

Written by the indexing model from the issue text.