fix SonarQube issues: mainly unused imports

src/routes/(angemeldet)/+layout.server.ts

@@ -1,8 +1,6 @@
 import { type ServerLoadEvent } from '@sveltejs/kit';
 import type { PageServerLoad } from '../anmeldung/$types';
 
-import { ROUTE_NAMES } from '..';
-
 export const load: PageServerLoad = (event: ServerLoadEvent) => {
 	if (event.locals.user) {
 		return {

src/routes/(angemeldet)/upload/+page.server.ts

@@ -1,10 +1,8 @@
 import { Readable } from 'stream';
 import { BUCKET, client } from '$lib/minio';
 import { fail, error } from '@sveltejs/kit';
-import { v4 as uuidv4 } from 'uuid';
 
-import { db } from '$lib/server/dbService';
-import { getVorgangByName, vorgangNameExists } from '$lib/server/vorgangService';
+import { getVorgangByName } from '$lib/server/vorgangService';
 
 const isRequiredFieldValid = (value: unknown) => {
 	if (value == null) return false;

src/routes/api/users/[user]/+server.ts

@@ -1,4 +1,3 @@
-import { json } from '@sveltejs/kit';
 import { deleteUser } from '$lib/server/userService';
 
 export async function DELETE({ params }) {