Validate custom resources against the CRDs a chart ships - #3

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: azure/setup-helm@b9e51907a09c216f16ebe8536097933489208112. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/