Bump System.Text.Json from 8.0.2 to 8.0.3 (#231)

Bumps [System.Text.Json](https://github.com/dotnet/runtime) from 8.0.2 to 8.0.3.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v8.0.2...v8.0.3)

---
updated-dependencies:
- dependency-name: System.Text.Json
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

samples/Serialization/Serialization.csproj

@@ -10,7 +10,7 @@
 
     <ItemGroup>
         <PackageReference Include="Dunet" Version="1.11.2" />
-        <PackageReference Include="System.Text.Json" Version="8.0.2" />
+        <PackageReference Include="System.Text.Json" Version="8.0.3" />
     </ItemGroup>
 
 </Project>