Bump GraphQL and GraphQL.SystemTextJson in /src

Bumps [GraphQL](https://github.com/graphql-dotnet/graphql-dotnet) and [GraphQL.SystemTextJson](https://github.com/graphql-dotnet/graphql-dotnet). These dependencies needed to be updated together.

Updates `GraphQL` from 8.4.1 to 8.5.0
- [Release notes](https://github.com/graphql-dotnet/graphql-dotnet/releases)
- [Commits](graphql-dotnet/graphql-dotnet@8.4.1...8.5.0)

Updates `GraphQL.SystemTextJson` from 8.4.1 to 8.5.0
- [Release notes](https://github.com/graphql-dotnet/graphql-dotnet/releases)
- [Commits](graphql-dotnet/graphql-dotnet@8.4.1...8.5.0)

---
updated-dependencies:
- dependency-name: GraphQL
  dependency-version: 8.5.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: GraphQL.SystemTextJson
  dependency-version: 8.5.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/Directory.Packages.props

@@ -6,11 +6,11 @@
   <ItemGroup>
     <PackageVersion Include="FluentValidation" Version="11.11.0" />
     <PackageVersion Include="FluentValidation.DependencyInjectionExtensions" Version="11.11.0" />
-    <PackageVersion Include="GraphQL" Version="8.4.1" />
+    <PackageVersion Include="GraphQL" Version="8.5.0" />
     <PackageVersion Include="GraphQL.MicrosoftDI" Version="8.4.1" />
     <PackageVersion Include="GraphQL.Server.Transports.AspNetCore" Version="8.2.0" />
     <PackageVersion Include="GraphQL.Server.Ui.GraphiQL" Version="8.2.0" />
-    <PackageVersion Include="GraphQL.SystemTextJson" Version="8.4.1" />
+    <PackageVersion Include="GraphQL.SystemTextJson" Version="8.5.0" />
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="27.0.2" />
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.4" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.4" />