Update @mui/x-date-pickers requirement in /src-admin

Updates the requirements on [@mui/x-date-pickers](https://github.com/mui/mui-x/tree/HEAD/packages/x-date-pickers) to permit the latest version.
- [Release notes](https://github.com/mui/mui-x/releases)
- [Changelog](https://github.com/mui/mui-x/blob/v7.28.2/CHANGELOG.md)
- [Commits](https://github.com/mui/mui-x/commits/v7.28.2/packages/x-date-pickers)

---
updated-dependencies:
- dependency-name: "@mui/x-date-pickers"
  dependency-version: 7.28.2
  dependency-type: direct:development
...

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

Author: dependabot[bot]

src-admin/package.json

@@ -22,7 +22,7 @@
         "@iobroker/json-config": "7.6.14",
         "@mui/icons-material": "^6.4.11",
         "@mui/material": "^6.4.11",
-        "@mui/x-date-pickers": "^7.29.1",
+        "@mui/x-date-pickers": "^8.1.0",
         "@types/react": "^18.3.20",
         "@types/react-dom": "^18.3.6",
         "date-fns": "^4.1.0",