chore(deps): update hotchocolate monorepo to v15

Author: renovate[bot]

Server/Server.csproj

@@ -11,8 +11,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="HotChocolate.AspNetCore" Version="13.6.1" />
-    <PackageReference Include="HotChocolate.AspNetCore.CommandLine" Version="13.6.1" />
+    <PackageReference Include="HotChocolate.AspNetCore" Version="15.1.5" />
+    <PackageReference Include="HotChocolate.AspNetCore.CommandLine" Version="15.1.5" />
     <PackageReference Include="ApolloGraphQL.HotChocolate.Federation" Version="1.3.0" />
   </ItemGroup>