fix: package.json & package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-CKEDITOR4-2430344
- https://snyk.io/vuln/SNYK-JS-NODEFORGE-2430337
- https://snyk.io/vuln/SNYK-JS-NODEFORGE-2430339
- https://snyk.io/vuln/SNYK-JS-NODEFORGE-2430341

package.json

@@ -17,7 +17,7 @@
     "bootstrap": "~4.3",
     "bootstrap-sass": "^3.4.1",
     "bootstrap3": "npm:bootstrap@~3.4",
-    "ckeditor4": "4.14.0",
+    "ckeditor4": "4.18.0",
     "cookieconsent": "^3.1.0",
     "cross-env": "^5.1.6",
     "eonasdan-bootstrap-datetimepicker": "^4.17.47",
@@ -27,7 +27,7 @@
     "jquery": "^3.5.1",
     "jquery-pjax": "~2.0",
     "js-yaml": "^3.14.0",
-    "laravel-mix": "^6.0.25",
+    "laravel-mix": "^6.0.30",
     "leaflet": "^1.3.4",
     "leaflet-ajax": "2.1.0",
     "leaflet-providers": "1.0.*",