Bump Microsoft.NET.Test.Sdk from 16.8.0 to 16.8.3 (#112)

Author: dependabot[bot]

WebDriverManager.Tests/WebDriverManager.Tests.csproj

@@ -8,7 +8,7 @@
 
     <ItemGroup>
         <PackageReference Include="coverlet.msbuild" Version="2.9.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
         <PackageReference Include="Selenium.WebDriver" Version="3.141.0" />
         <PackageReference Include="xunit" Version="2.4.1" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />