Remove support for React 17

[kerams]

Closes #98

[et1975]

Thanks @kerams, it seems our builds have rotted away :/
We need to get them to passing again, would you be able to fix that as well?

[kerams]

Ready

[et1975]

@MangelMaxime sorry, I didn't wait for your feedback, but would still like to see it.
Also not sure if we should do a major version bump, as it has breaking dependency changes.

[et1975]

@kerams do you have a test project that you've tried this on?
I usually update one of the samples to use the local build of elimish/react to try it out.

[kerams]

I haven't tried these changes, but it's very straightforward. All I did was remove the <18 branches. A prerelease is fine if you want to be extra careful. Agree with a major bump.

[MangelMaxime]

@et1975 I made a quick test locally and it seems to be working fine.

IHMO A new major release make sense, once done I will need to make a new release for Elmish.HMR too I think.

[kerams]

Could you make a (pre)release please?

[et1975]

Created v5.x branch, will release from it later.

[et1975]

released as 5.0.0-beta-2

[kerams]

Cheers. Works fine with React 19, HMR too.