chore(deps): update dependency microsoft.net.test.sdk to v17.6.3 (#46)

Author: renovate[bot]

tests/Prometheus.Client.AspNetCore.Tests.csproj

@@ -32,7 +32,7 @@
     <PackageReference Include="xunit" Version="2.4.2" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp2.2' AND '$(TargetFramework)' != 'netcoreapp3.0'">
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.2" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp2.2' OR '$(TargetFramework)' == 'netcoreapp3.0'">