Exclude node 22

[lizkenyon]

WHY are these changes introduced?

• Related to Internal server error: Unexpected identifier 'assert' #695
• Node 22 removes import type assertions which are used in the shopify-app-remix library
• We are investigating the fix for this, but until then we do not want to allow user to use node 22

Test this PR

npm init @shopify/app@latest -- --template=https://github.com/Shopify/shopify-app-template-remix.git#<your-branch-name>

exclude-node-22.mp4

Checklist

Note: once this PR is merged, it becomes a new release for this template.

• I have added/updated tests for this change
• I have made changes to the README.md file and other related documentation, if applicable