🎨(frontend) get the brand logo from the theme

We want to get the brand logo from the theme.
This way, we will be able to change the
logo easily just by switching to another theme.

src/frontend/apps/e2e/__tests__/app-impress/header.spec.ts

@@ -10,11 +10,7 @@ test.describe('Header', () => {
   test('checks all the elements are visible', async ({ page }) => {
     const header = page.locator('header').first();
 
-    await expect(header.getByAltText('Marianne Logo')).toBeVisible();
-
-    await expect(
-      header.getByAltText('Freedom Equality Fraternity Logo'),
-    ).toBeVisible();
+    await expect(header.getByAltText('Gouvernement Logo')).toBeVisible();
 
     await expect(header.getByAltText('Docs Logo')).toBeVisible();
     await expect(header.locator('h2').getByText('Docs')).toHaveCSS(