rounded corner clip is applied before blur

### What Happened?

It appears blur is applied after the rounded corner clip so if you have blur near the edges it fuzzes them out:

### Steps to Reproduce

Test with https://github.com/elementary/wingpanel/pull/678

### Expected Behavior

rounded corner clip should be applied last to make sure the corners are nice and crispy

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_