Latest ESLint now expects the new config file format, so the fixture directories now include an eslint.config.js file.
Latest ESLint expects structuredClone to be present; it was added in Node 17, so we'll make Node 18 the oldest version of Node we test on.
(I don't think this package needs an official support policy regarding Node; the deal is that, if your version of ESLint (>= version 8) works on the command line for your project, it'll work in this package, since the point is to use the same version of Node to run the worker process as you've got set up for your project.)
Two main causes of the CI breakage:
eslint.config.jsfile.structuredCloneto be present; it was added in Node 17, so we'll make Node 18 the oldest version of Node we test on.(I don't think this package needs an official support policy regarding Node; the deal is that, if your version of ESLint (>= version 8) works on the command line for your project, it'll work in this package, since the point is to use the same version of Node to run the worker process as you've got set up for your project.)