Bump @mui/material from 5.15.2 to 5.15.16

Bumps [@mui/material](https://github.com/mui/material-ui/tree/HEAD/packages/mui-material) from 5.15.2 to 5.15.16.
- [Release notes](https://github.com/mui/material-ui/releases)
- [Changelog](https://github.com/mui/material-ui/blob/v5.15.16/CHANGELOG.md)
- [Commits](https://github.com/mui/material-ui/commits/v5.15.16/packages/mui-material)

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

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

package.json

@@ -7,7 +7,7 @@
     "@emotion/styled": "^11.11.0",
     "@fontsource-variable/roboto-flex": "^5.0.3",
     "@iarna/toml": "^2.2.5",
-    "@mui/material": "^5.15.2",
+    "@mui/material": "^5.15.16",
     "@opencast/appkit": "^0.2.4",
     "@reduxjs/toolkit": "^2.0.1",
     "@testing-library/jest-dom": "^6.4.2",