Update linting

[goosewobbler]

We need to address the issue fixed by #578.

Updating the linting to use un-ts/eslint-plugin-import-x@master/docs/rules/no-extraneous-dependencies.md should cover it.

Additionally, ESLint v9 has been released and once the new version of @typescript-eslint is out we should be good to upgrade. Prior art: #598

Alternative: Biome (would replace Prettier and most ESLint plugins)
https://biomejs.dev/linter/rules/no-undeclared-dependencies/

[goosewobbler]

Went with eslint-plugin-import-x, will switch to Biome + ESLint at some point when Biome is a bit more established.