Add support for Ruby 3.1 and Rails 7.0

This issue is a (choose one):

• Problem/bug report.
• Feature request.
• Request for support. Note: Please try to avoid submitting issues for support requests. Use Gitter instead.

Checklist before submitting:

• I've searched for an existing issue.
• I've asked my question on Gitter and have not received a satisfactory answer.
• I've included a complete bug report template. This step helps us and allows us to see the bug without trying to reproduce the problem from your description. It helps you because you will frequently detect if it's a problem specific to your project.
• The feature I'm asking for is compliant with the JSON:API spec.

Description

Features:

jsonapi-resources should support Ruby 3.1 and Rails 7.0, as these are now the most recently released versions of Ruby and Rails respectively. To ensure that these versions are supported, they need to be included in the CI matrix.

Beginne damit, die CI-Matrix und ihre vorhandenen Einträge für Ruby- und Rails-Versionen zu finden. Aktualisiere die Matrix, sodass Ruby 3.1 und Rails 7.0 enthalten sind, und führe anschließend die CI-Prüfungen aus, um zu bestätigen, dass die neuen Kombinationen erfolgreich sind.