Update to eslint 9 (#40555)

Eslint 9 brings a new config format, which means this PR also rewrites
all the eslint configs. I took the opportunity to clean them up
(although a good bit of that wound up in earlier PRs), and added code to
fetch the textdomain from composer.json and whether the project uses
React from package.json so we don't need to have so many boilerplate
configs that just set a textdomain or enable React rules.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/12280005125

Upstream-Ref: Automattic/jetpack@9e3ae2f

Author: anomiex

.gitattributes

@@ -19,8 +19,6 @@ package.json      export-ignore
 # Files to exclude from the mirror repo, but included in the monorepo.
 # Remember to end all directories with `/**` to properly tag every file.
 .gitignore        production-exclude
-.eslintignore     production-exclude
-.eslintrc.cjs     production-exclude
 .phpcs.dir.xml    production-exclude
 changelog/**      production-exclude
 phpunit.xml.dist  production-exclude