Update dependencies - spring boot 4 and angular 21 (#10)

Co-authored-by: Florian THIERRY
Reviewed-on: #10

frontend/src/app/app.component.ts

@@ -1,20 +1,18 @@
-import { CommonModule } from '@angular/common';
+
 import { Component } from '@angular/core';
 import { RouterOutlet } from '@angular/router';
 import { HeaderComponent } from './components/header/header.component';
 import { FooterComponent } from './components/footer/footer.component';
 
 @Component({
-  selector: 'app-root',
-  standalone: true,
-  imports: [
-    CommonModule,
+    selector: 'app-root',
+    imports: [
     RouterOutlet,
     HeaderComponent,
     FooterComponent
-  ],
-  templateUrl: './app.component.html',
-  styleUrl: './app.component.scss'
+],
+    templateUrl: './app.component.html',
+    styleUrl: './app.component.scss'
 })
 export class AppComponent {
   title = 'codiki-ng';