Update to eslint 9

[solaris007]

Currently the helix-eslint-config is incompatible with eslint v9+ as the config format changed and is is not backwards compatible.

In order to benefit from continued eslint updates we should consider updating helix-eslint-config and its extended configs accordingly.

eslint-config-airbnb-base (+ plugins) support for eslint 9 is currently being worked on.

[dominique-pfister]

We also use plugins, e.g. eslint-plugin-import, that do not support eslint 9, yet.