chore(deps): update vitest to v2 (major) (#13144)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

packages/vant/package.json

@@ -61,7 +61,7 @@
     "@vant/icons": "workspace:*",
     "@vitejs/plugin-vue": "^5.1.4",
     "@vitejs/plugin-vue-jsx": "^4.0.1",
-    "@vitest/coverage-istanbul": "^1.6.0",
+    "@vitest/coverage-istanbul": "^2.1.2",
     "@vue/runtime-core": "^3.5.11",
     "@vue/test-utils": "^2.4.6",
     "csstype": "^3.1.3",
@@ -69,7 +69,7 @@
     "jsdom": "^25.0.1",
     "typescript": "^5.6.2",
     "vite": "^5.4.8",
-    "vitest": "^1.6.0",
+    "vitest": "^2.1.2",
     "vitest-canvas-mock": "^0.3.3",
     "vue": "^3.5.11",
     "vue-router": "^4.4.5"