[Avatar] Avoid use of z-index

[nvdai2401]

• I have followed (at least) the PR section of the contributing guide.

Closes: #21562

[mui-pr-bot]

Details of bundle changes

Generated by 🚫 dangerJS against 039bae5

[oliviertassinari]

Thanks for spending time on this :)

• What's the direction prop for? I fail to see the use case for it
• The incentive for changing the implementation was to remove the usage of z-index that can mess with the stacking context of other elements. Could we remove it?

[nvdai2401]

What's the direction prop for? I fail to see the use case for it

The direction prop is used for change the stack direction if we want it to stack RTL or LTR. I see you and ZChenzy discuss in #21562. Should we add this feature for AvatarGroup?

The incentive for changing the implementation was to remove the usage of z-index that can mess with the stacking context of other elements. Could we remove it?

Yes, we can. @oliviertassinari

[oliviertassinari]

The direction prop is used for change the stack direction if we want it to stack RTL or LTR.

I don't see why we would want to support it. In any case, it's a different concern to the problem we are trying to solve. Please remove it. We can continue the discussion and evalute if worth adding for a future pull request.

Yes, we can.

Great, let's do that.

[oliviertassinari]

@nvdai2401 It's a great first pull request on Material-UI 👌🏻. Thank you for working on it!

[CWSites]

How am I able to tell which release this made it into?

[oliviertassinari]

@CWSites Check the pull request number (#21685) in the changelog.