Aliasing with @ is not recognized as 'internal'

[ombene]

This seems to be a repeat of an issue that has been resolved and regressed twice now, see #2145 and #2249.

In my case the source code is private, but we're using a config that looks like:

// ...
"import/resolver": {
  "alias": [
    ["@", "./src"]
  ]
}
// ...

(See also https://github.com/johvin/eslint-import-resolver-alias.) And with source code like:

// ...
import exampleInternalViaAlias from '@/exampleInternalViaAlias';

import exampleSibling from './exampleSibling';
// ...

When upgrading to v2.25.3 from v2.22.1, without any other changes to source code or other dependencies, we have now started getting false negatives like:

  3:1  error  `@/exampleInternalViaAlias` import should occur after import of `./exampleSibling`  import/order

Injecting some logs into the installed version of eslint-plugin-import in our node_modules, I can see that the import type is getting calculated as 'unknown' (instead of 'internal') for '@/exampleInternalViaAlias'.