[Bug Report][3.5.8] Expansion Panels (variant Accordion) have no rounded corners when having 1 single expansion panel component

[kilarn123]

Environment

Vuetify Version: 3.5.8
Vue Version: 3.4.21
Browsers: Edge 122.0.0.0
OS: Windows 10

Steps to reproduce

• Create a v-expansion-panels with variant="accordion"
• Add only one child : v-expansion-panel with rounded="xl"

Expected Behavior

the expansion panel should be rounded

Actual Behavior

It's only rounded if multiple expansion panels are present

Reproduction Link

https://play.vuetifyjs.com/#...

Other comments

Probably heavily linked to this issue :
#16019
It has fixed the other variants but not variant="accordion"

[kilarn123]

temporary fix

<!-- variant default if length === 1 (vuetify #19379) -->
<v-expansion-panels :variant="mylist.length === 1 ? 'default' : 'accordion'">