[codemod] v6.0.0/sx-prop produces strange changes

[LukasTy]

Steps to reproduce

Link to live example: (required)

Steps:

1. Run npx @mui/codemod@next v6.0.0/sx-prop docs or npx @mui/codemod@next v6.0.0/sx-prop packages on the latest mui-x master branch
2. Observe strange diffs like this:

Current behavior

The codemod "duplicates" the existing sx declaration without any meaningful need to do it.

Expected behavior

The existing sx prop would be left as is in such case.

Context

No response

Your environment

npx @mui/envinfo

System:
    OS: macOS 14.5
  Binaries:
    Node: 18.20.2 - ~/.nvm/versions/node/v18.20.2/bin/node
    npm: 10.5.0 - ~/.nvm/versions/node/v18.20.2/bin/npm
    pnpm: 9.6.0 - ~/.nvm/versions/node/v18.20.2/bin/pnpm
  Browsers:
    Chrome: 127.0.6533.89
    Edge: 127.0.2651.86
    Safari: 17.5
  npmPackages:
    @emotion/react: ^11.13.0 => 11.13.0 
    @emotion/styled: ^11.13.0 => 11.13.0 
    @mui/icons-material: ^5.16.5 => 5.16.5 
    @mui/internal-markdown: ^1.0.8 => 1.0.8 
    @mui/internal-test-utils: ^1.0.5 => 1.0.5 
    @mui/material: ^5.16.5 => 5.16.5 
    @mui/monorepo: github:mui/material-ui#4a82b6b0e0395db8fa0a0d49b6b76de4516b1579 => 6.0.0-beta.4 
    @mui/utils: ^5.16.5 => 5.16.5 
    @types/react: ^18.3.3 => 18.3.3 
    react: ^18.3.1 => 18.3.1 
    react-dom: ^18.3.1 => 18.3.1 
    typescript: ^5.5.4 => 5.5.4 

Search keywords: codemod, sx-prop

[mnajdova]

Looks like a bug, cc @siriwatknp

[siriwatknp]

Looks like a bug, cc @siriwatknp

Yes, I'm working on it.