Bump vitest from 2.1.9 to 4.0.9 in /src/Bicep.MSBuild.E2eTests

Bumps [vitest](https://github.com/vitest-dev/vitest/tree/HEAD/packages/vitest) from 2.1.9 to 4.0.9.
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.9/packages/vitest)

---
updated-dependencies:
- dependency-name: vitest
  dependency-version: 4.0.9
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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Author: dependabot[bot]