Bump Microsoft.NET.Test.Sdk from 17.14.1 to 18.0.0 (#39)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup Label="Test dependencies">
     <MSTestVersion>3.10.4</MSTestVersion>
-    <MicrosoftNETTestSdkVersion>17.14.1</MicrosoftNETTestSdkVersion>
+    <MicrosoftNETTestSdkVersion>18.0.0</MicrosoftNETTestSdkVersion>
   </PropertyGroup>
 </Project>