Non-lethal error log on start.sh

Nobody has claimed this yet.

This isn't a standard Support Inquiry, but I am seeing this error when running start.sh:
```
2024-05-05T02:17:18.861Z info: [lively.modules package] Unable loading package config file:///home/rick/lively.next/local_projects/custom-npm-modules/package.json for package: [ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/custom-npm-modules/package.json'
Instantiating /home/rick/lively.next/local_projects/custom-npm-modules/package.json
Loading /home/rick/lively.next/local_projects/custom-npm-modules/package.json
Error: ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/custom-npm-modules/package.json'] {
originalErr: [Error: ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/custom-npm-modules/package.json'] {
errno: -2,
code: 'ENOENT',
syscall: 'open',
path: '/home/rick/lively.next/local_projects/custom-npm-modules/package.json'
}
}
2024-05-05T02:17:18.887Z info: [lively.modules package] Unable loading package config file:///home/rick/lively.next/local_projects/lively.next-node_modules/package.json for package: [ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/lively.next-node_modules/package.json'
Instantiating /home/rick/lively.next/local_projects/lively.next-node_modules/package.json
Loading /home/rick/lively.next/local_projects/lively.next-node_modules/package.json
Error: ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/lively.next-node_modules/package.json'] {
originalErr: [Error: ENOENT: no such file or directory, open '/home/rick/lively.next/local_projects/lively.next-node_modules/package.json'] {
errno: -2,
code: 'ENOENT',
syscall: 'open',
path: '/home/rick/lively.next/local_projects/lively.next-node_modules/package.json'
}
}
```

**Version**: Please paste the lively.next commit on which the problem occurred here (use the copy button of the Version Checker in the bottom left corner).
97874fc6b9ca2be74bda64de4c9a687d3e8d4f8f

Reproduce the report by running start.sh and inspect how it handles the missing package.json files under local_projects/custom-npm-modules and local_projects/lively.next-node_modules. Determine whether these paths are expected during startup, then verify that startup logs no misleading error for an expected absence while still reporting real failures.

Written by the indexing model from the issue text.