revert back to the standard eslint parser

[obiot]

we had to (temporarily) switch to the babel parser because of the new import assertion syntax, added as part of the migration to rollup 3 (#1142)

see https://stackoverflow.com/questions/71090960/is-there-a-way-to-make-eslint-understand-the-new-import-assertion-syntax-without

so, as soon as it enters stage 4, we should revert to the previous eslint config.