Bump flatted from 3.2.7 to 3.4.2 in /src/webapp/setup

Bumps [flatted](https://github.com/WebReflection/flatted) from 3.2.7 to 3.4.2.
- [Commits](https://github.com/WebReflection/flatted/compare/v3.2.7...v3.4.2)

---
updated-dependencies:
- dependency-name: flatted
  dependency-version: 3.4.2
  dependency-type: indirect
...

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

src/webapp/setup/package-lock.json

@@ -1497,10 +1497,11 @@
       }
     },
     "node_modules/flatted": {
-      "version": "3.2.7",
-      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.2.7.tgz",
-      "integrity": "sha512-5nqDSxl8nn5BSNxyR3n4I6eDmbolI6WT+QqR547RwxQapgjQBmtktdP+HTBb/a/zLsbzERTONyUB5pefh5TtjQ==",
-      "dev": true
+      "version": "3.4.2",
+      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.4.2.tgz",
+      "integrity": "sha512-PjDse7RzhcPkIJwy5t7KPWQSZ9cAbzQXcafsetQoD7sOJRQlGikNbx7yZp2OotDnJyrDcbyRq3Ttb18iYOqkxA==",
+      "dev": true,
+      "license": "ISC"
     },
     "node_modules/fs.realpath": {
       "version": "1.0.0",