Bump Microsoft.NET.Test.Sdk from 16.7.1 to 16.8.3 (#196)

Author: dependabot-preview[bot]

src/common.props

@@ -16,7 +16,7 @@
   <PropertyGroup>
     <XunitVersion>2.4.1</XunitVersion>
     <XunitRunnerVersion>2.4.3</XunitRunnerVersion>
-    <TestSdkVersion>16.7.1</TestSdkVersion>
+    <TestSdkVersion>16.8.3</TestSdkVersion>
     <NBenchVersion>1.2.2</NBenchVersion>
   </PropertyGroup>
 </Project>