Bump System.ServiceModel.Primitives in /src/STIL.ServiceClient.Tests

Bumps [System.ServiceModel.Primitives](https://github.com/dotnet/wcf) from 4.10.2 to 4.10.3.
- [Release notes](https://github.com/dotnet/wcf/releases)
- [Commits](https://github.com/dotnet/wcf/commits)

---
updated-dependencies:
- dependency-name: System.ServiceModel.Primitives
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

src/STIL.ServiceClient.Tests/STIL.ServiceClient.Tests.csproj

@@ -37,7 +37,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
 
     <PackageReference Include="Moq" Version="4.20.69" />
-    <PackageReference Include="System.ServiceModel.Primitives" Version="4.10.2" />
+    <PackageReference Include="System.ServiceModel.Primitives" Version="4.10.3" />
     <PackageReference Include="xunit" Version="2.6.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>