7 branch needs node 22

[tiberiuichim]

Describe the bug

Node that runs Eslint complains about missing structuredClone, which is present in node 22 but not node 20

To Reproduce
Steps to reproduce the behavior:

Clone the 7 branch, make install then try to run eslint on a file in the apps/seven folder

Expected behavior

Eslint should not crash

Screenshots
If applicable, add screenshots or videos to help explain your problem.

Software (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. firefox, chrome, safari]
• Volto Version [e.g. 18.4.0]
• Plone Version [e.g. 6.1.0]
• Plone REST API Version [e.g. 9.1.0]

Additional context
Add any other context about the problem here.

[davisagli]

I would expect the 7 app should only support Node 22 and above. It doesn't make sense to support an old LTS release for something that's still in development.