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

Co-authored-by: Florian THIERRY
Reviewed-on: florian/codiki-hexagonal#10

frontend/src/app/components/header/header.component.ts

@@ -1,4 +1,4 @@
-import { CommonModule } from '@angular/common';
+
 import { Component, inject } from '@angular/core';
 import { FormControl, ReactiveFormsModule } from '@angular/forms';
 import { MatButtonModule } from '@angular/material/button';
@@ -12,10 +12,8 @@ import { PublicationsSearchBarComponent } from '../publications-search-bar/publi
 import { SideMenuComponent } from '../side-menu/side-menu.component';
 
 @Component({
-  selector: 'app-header',
-  standalone: true,
-  imports: [
-    CommonModule,
+    selector: 'app-header',
+    imports: [
     MatButtonModule,
     MatIconModule,
     MatMenuModule,
@@ -24,10 +22,10 @@ import { SideMenuComponent } from '../side-menu/side-menu.component';
     PublicationsSearchBarComponent,
     ReactiveFormsModule,
     RouterModule,
-    SideMenuComponent,
-  ],
-  templateUrl: './header.component.html',
-  styleUrl: './header.component.scss',
+    SideMenuComponent
+],
+    templateUrl: './header.component.html',
+    styleUrl: './header.component.scss'
 })
 export class HeaderComponent {
   private authenticationService = inject(AuthenticationService);