Support eslint v9+

[BigBlueHat]

Following the README instructions for installation currently fail. Downgrading eslint to ^8.52.0 solves the issue...for now. Short term, we an update the README. Long term, we should support eslint v9+.

$ npm i -D eslint

added 61 packages, and audited 277 packages in 3s

60 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
$ npm i -D eslint-config-digitalbazaar
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: package-name0.0.2
npm ERR! Found: eslint@9.0.0
npm ERR! node_modules/eslint
npm ERR!   dev eslint@"^9.0.0" from the root project
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer eslint@"^8.14.0" from eslint-config-digitalbazaar@5.0.1
npm ERR! node_modules/eslint-config-digitalbazaar
npm ERR!   dev eslint-config-digitalbazaar@"*" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
...

[davidlehn]

For reference:
https://eslint.org/blog/2024/04/eslint-v9.0.0-released/
https://eslint.org/docs/latest/use/migrate-to-9.0.0

They even built in a web server with config inspector:
https://eslint.org/blog/2024/04/eslint-config-inspector/

This update will require some experimentation. I think our bits can be updated easily enough. But we almost always are pulling in rules for jsdoc, vue, modules, etc and we'll have to see how compatible all that is.