chore: bump the mui group across 1 directory with 3 updates

Bumps the mui group with 3 updates in the /react-app directory: [@mui/icons-material](https://github.com/mui/material-ui/tree/HEAD/packages/mui-icons-material), [@mui/material](https://github.com/mui/material-ui/tree/HEAD/packages/mui-material) and [@mui/system](https://github.com/mui/material-ui/tree/HEAD/packages/mui-system).


Updates `@mui/icons-material` from 5.16.12 to 6.4.1
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/v6.4.1/packages/mui-icons-material)

Updates `@mui/material` from 5.16.12 to 6.4.1
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/v6.4.1/packages/mui-material)

Updates `@mui/system` from 5.16.12 to 6.4.1
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/v6.4.1/packages/mui-system)

---
updated-dependencies:
- dependency-name: "@mui/icons-material"
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: mui
- dependency-name: "@mui/material"
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: mui
- dependency-name: "@mui/system"
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: mui
...

Signed-off-by: dependabot[bot] <[email protected]>