[website] Update MUI logos to be consistent

[oliviertassinari]

Steps to reproduce

Steps:

1. There are several different variants of the MUI logo used on the website.

Current behavior

Inconsistent. See https://groups.google.com/a/mui.com/g/devex/c/7WjonmQXsuo/m/SaOYuFhKBwAJ

Expected behavior

Consistent. The version in Figma is correct https://www.figma.com/design/nNAatyLlRl3Tq4nGHgAmNh/Primitives?node-id=6579-45201&t=CWYB5mXxgVMwRsnt-0.

Context

Your environment

npx @mui/envinfo

  Don't forget to mention which browser you used.
  Output from `npx @mui/envinfo` goes here.

Search keywords: -

[linear]

MAT-1788