actions-toolkit: Add JsPlainObjects, eg core/InputOptions

[hfhbd]

Is your feature request related to a problem? Please describe.
Some projects use the new JsPlainObjects annotation from Kotlin 2.0.0, but not actions-toolkit.

Describe the solution you'd like

Describe alternatives you've considered

Additional context
Do you have any pointer to create a PR? It's declared here but I am lost.

[turansky]

Hi @hfhbd! Thank you for reporting!
We should test it at start on base libraries (where JSO interfaces marked in specifications/IDLs), when Kotlin 2.0 will be released.
After that we will continue work with compiler checks, which don't work in K1.