Bump vitest from 3.2.4 to 4.1.5 in /src/vscode-bicep-ui

Bumps [vitest](https://github.com/vitest-dev/vitest/tree/HEAD/packages/vitest) from 3.2.4 to 4.1.5.
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.1.5/packages/vitest)

---
updated-dependencies:
- dependency-name: vitest
  dependency-version: 4.1.5
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/vscode-bicep-ui/apps/deploy-pane/package.json

@@ -27,7 +27,7 @@
     "typescript": "^5.7.3",
     "vite": "^7.3.2",
     "vite-plugin-ejs": "^1.7.0",
-    "vitest": "^3.2.4"
+    "vitest": "^4.1.5"
   },
   "dependencies": {
     "@azure/arm-resources": "^5.2.0",