v6.0.0-alpha.1: Drawer backdrop has no transition on close #43024

Prerequisites

• I have searched for duplicate or closed issues
• I have validated any HTML to avoid common problems
• I have read the contributing guidelines

Describe the issue

Hello,

I noticed some inconsistency in backdrop transition between Dialog and Drawer components.

In Bootstrap 5, backdrop in both Modal and Offcanvas is closed with transition. But in Bootstrap 6, only Dialog backdrop has transition on close - in Drawer, backdrop is dropped immediately after click on Close button.
With default Bootstrap 6 styling it's hard to see this because backdrop in Drawer is transparent (only blur is applied), but I wanted Drawer to look more like BS5 Offcanvas, so I applied dark backdrop by overriding --bs-drawer-backdrop-bg var (you can see this in reproducer below).

Is there a chance to apply the same behavior for both Dialog and Drawer?

Thank you!

Reduced test cases

Here are the reproducers (single HTML files):

Bootstrap 5: both backdrops close with transition
Bootstrap 6: Drawer backdrop close without transition

What operating system(s) are you seeing the problem on?

Linux

What browser(s) are you seeing the problem on?

Firefox

What version of Bootstrap are you using?

v6.0.0-alpha.1