chore(deps): update dependency microsoft.net.test.sdk to v17.3.1

Author: renovate[bot]

tests/Prometheus.Client.MetricServer.Tests.csproj

@@ -6,7 +6,7 @@
     <AssemblyOriginatorKeyFile>../Prometheus.Client.MetricServer.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <PackageReference Include="System.Text.RegularExpressions" Version="4.3.1" />
     <PackageReference Include="xunit" Version="2.4.2" />