Happy new year!
Is there any article on how to update VCP DCV 2022 to VCP DCV 2023?
what training will satisfy the requirement?
Yes, as that's when you completed the last of the requirements.
Current options are here - they will change as new courses and new exams are released.
https://www.vmware.com/learning/certification/vcp-dcv.html
Best course of action in terms of training or certification, or the actual software upgrade?
If you meant training and certification, you can take vSphere 7 training on demand even if you can’t find live classes on that version, and the latest exam is on 7.0 - complete both and you’ll have the VCP.
vSphere 8 based VCP-DCV exam 2V0-21.23 has just been announced.