refactor: remove deprecated dependency

Author: OliverDudgeon

package.json

@@ -45,7 +45,6 @@
     "@mui/lab": "6.0.0-beta.25",
     "@mui/material": "6.4.2",
     "@mui/material-nextjs": "6.4.2",
-    "@mui/styles": "6.4.2",
     "@next/mdx": "15.1.6",
     "@rjsf/core": "5.24.8",
     "@rjsf/mui": "5.24.8",
@@ -54,7 +53,7 @@
     "@sentry/nextjs": "8.55.0",
     "@squonk/account-server-client": "4.2.0-rc.3",
     "@squonk/data-manager-client": "3.3.1",
-    "@squonk/mui-theme": "4.0.0",
+    "@squonk/mui-theme": "5.0.0",
     "@squonk/sdf-parser": "1.3.0",
     "@tanstack/match-sorter-utils": "8.19.4",
     "@tanstack/react-query": "5.69.0",