#### DESCRIPTION The JSON:API specification has been [updated](https://github.com/json-api/json-api/pull/1532) to require what we did for sparse fieldsets in #996 to also apply for includes. #### STEPS TO REPRODUCE 1. Create a custom resource definition that silently includes a relationship 2. Execute GET request with query string `?include=` #### EXPECTED BEHAVIOR The response body contains ~either~ an empty `include` array ~or omits it entirely~. #### ACTUAL BEHAVIOR HTTP 400 Bad Request. #### VERSIONS USED - JsonApiDotNetCore version: 5.0.3 - ASP.NET Core version: 6.0 - Entity Framework Core version: N/A - Database provider: N/A