Cannot load a stylesheet using with_custom_head in dioxus 0.6

**Problem**

In dioxus 0.5, we can use the method [`with_custom_head`](https://docs.rs/dioxus-desktop/latest/dioxus_desktop/struct.Config.html#method.with_custom_head) to load a stylesheet like:

```html

```
But it does not work in dioxus 0.6. Any ideas on how to load a local stylesheet using `with_custom_head` (not using asset!)?

If we use `asset!`, it seems that it can not run with `cargo run`.

**Steps To Reproduce**

Steps to reproduce the behavior:

- Call the `with_custom_head` method to load a stylesheet in a local dir.

**Expected behavior**

The `with_custom_head` method should work as dioxus 0.5.

**Screenshots**

**Environment:**
- Dioxus version: 0.6
- Rust version: 1.83
- OS info: Windows
- App platform: `desktop`

**Questionnaire**

I'm interested in fixing this myself but don't know where to start