chore(deps): update vitest monorepo to v4.1.6

Author: renovate[bot]

frontend/package.json

@@ -55,9 +55,9 @@
         "@types/testing-library__react": "10.2.0",
         "@uswds/compile": "1.3.2",
         "@vitejs/plugin-react": "6.0.1",
-        "@vitest/coverage-istanbul": "4.1.5",
+        "@vitest/coverage-istanbul": "4.1.6",
         "@vitest/eslint-plugin": "1.6.16",
-        "@vitest/ui": "4.1.5",
+        "@vitest/ui": "4.1.6",
         "axe-core": "4.11.4",
         "cypress": "15.14.2",
         "cypress-axe": "1.7.0",
@@ -84,7 +84,7 @@
         "vite": "8.0.10",
         "vite-plugin-eslint": "1.8.1",
         "vite-plugin-svgr": "5.2.0",
-        "vitest": "4.1.5",
+        "vitest": "4.1.6",
         "storybook": "10.3.6",
         "@storybook/react-vite": "10.3.6",
         "@chromatic-com/storybook": "5.1.2",
@@ -93,7 +93,7 @@
         "@storybook/addon-onboarding": "10.3.6",
         "prop-types": "15.8.1",
         "eslint-plugin-storybook": "10.3.6",
-        "@vitest/coverage-v8": "4.1.5"
+        "@vitest/coverage-v8": "4.1.6"
     },
     "scripts": {
         "start": "bunx --bun vite",