test(frontend): replace jest with vitest

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/vitest.config.ts

@@ -0,0 +1,31 @@
+/*
+ * SPDX-FileCopyrightText: 2025 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+import { resolve } from 'path'
+
+export default defineConfig({
+  test: {
+    environment: 'jsdom',
+    exclude: ['cypress/**/*'],
+    alias: [
+      {
+        find: /^.+\\.(svg)$/,
+        replacement: resolve(__dirname, './src/test-utils/svg-mock.tsx')
+      },
+      {
+        find: /^react-bootstrap-icons$/,
+        replacement: resolve(__dirname, './src/test-utils/bootstrap-icon-mocks.tsx')
+      },
+      {
+        find: RegExp('^react-bootstrap-icons/dist/icons/.*$'),
+        replacement: resolve(__dirname, './src/test-utils/svg-mock.tsx')
+      }
+    ],
+    setupFiles: './vitest.setup.ts'
+  },
+  plugins: [react()]
+})