chore(deps): bump @ng-select/ng-select from 6.1.0 to 7.0.1 in /frontend

Bumps [@ng-select/ng-select](https://github.com/ng-select/ng-select) from 6.1.0 to 7.0.1.
- [Release notes](https://github.com/ng-select/ng-select/releases)
- [Changelog](https://github.com/ng-select/ng-select/blob/master/CHANGELOG.md)
- [Commits](ng-select/ng-select@v6.1.0...v7.0.1)

---
updated-dependencies:
- dependency-name: "@ng-select/ng-select"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

frontend/package.json

@@ -26,7 +26,7 @@
     "@angular/platform-browser": "~12.0.5",
     "@angular/platform-browser-dynamic": "~12.0.5",
     "@angular/router": "~12.0.5",
-    "@ng-select/ng-select": "^6.1.0",
+    "@ng-select/ng-select": "^7.0.1",
     "chart.js": "^2.9.4",
     "core-js": "^3.12.1",
     "jwt-decode": "^3.1.2",