Bump @mui/styles from 5.15.18 to 5.15.20

Bumps [@mui/styles](https://github.com/mui/material-ui/tree/HEAD/packages/mui-styles) from 5.15.18 to 5.15.20.
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/v5.15.20/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/v5.15.20/packages/mui-styles)

---
updated-dependencies:
- dependency-name: "@mui/styles"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -33,7 +33,7 @@
     "@emotion/styled": "^11.11.5",
     "@mui/icons-material": "^5.15.18",
     "@mui/material": "^5.15.18",
-    "@mui/styles": "^5.15.18",
+    "@mui/styles": "^5.15.20",
     "@mui/x-date-pickers": "~6.20.0",
     "@radix-ui/react-checkbox": "^1.0.4",
     "@radix-ui/react-slot": "^1.0.2",