Remove necroptimade base URL

[ml-evs]

This PR simply sets the necroptimade base URL to null, as I have not had time to redeploy it away from heroku (and may never).

[ml-evs]

Hmmm, looks like netlify have deprecated the image we were using for deployment https://app.netlify.com/sites/optimade-providers/deploys/63fcc995829b3d00086c145b

5:17:41 PM: ---------------------------------------------------------------------
  UNSUPPORTED BUILD IMAGE

  The build image for this site uses Ubuntu 16.04 Xenial Xerus, which is no longer supported.

  To enable builds for this site, select a later build image at the following link:
  https://app.netlify.com/sites/optimade-providers/settings/deploys#build-image-selection

  For more details, visit the build migration guide:
  https://answers.netlify.com/t/please-read-end-of-support-for-xenial-build-image-everything-you-need-to-know/68239
  ---------------------------------------------------------------------

@rartino is there any way you can share access to the netlify build, unless this is something you can readily fix yourself? I registered with my GitHub account (git@ml-evs.science if you need an email)

[rartino]

I've updated it, but I'm not sure how to trigger a rebuild for this PR.

It would be great to share access to the netlify between some of us, but at least last we investigated this, it cannot be done without paying. Hence, we have been holding our breaths for GitHub pages to start allowing specifying media types.

(And if you have any alternative hosting ideas, that would be welcome.)

[ml-evs]

I've updated it, but I'm not sure how to trigger a rebuild for this PR.

I've just triggered a deployment, lets see what it does...

It would be great to share access to the netlify between some of us, but at least last we investigated this, it cannot be done without paying. Hence, we have been holding our breaths for GitHub pages to start allowing specifying media types.

Yes, this felt like dejavu as I asked it... previously I would have suggested heroku but that is no longer free even for single users.

It looks like Cloudflare may now fill this niche for free, with e.g., Cloudflare Pages (looks like the best in terms of deploying from GH as a team) or maybe just a simple Cloudflare worker with heavy caching.

I'd be happy to investigate this before the next meeting, unless you'd rather do it sooner. I know there are caveats around static files, mime types and the various redirects but I'm sure cloudflare would be flexible enough...

[ml-evs]

Looks like the deployment worked, thanks @rartino! Happy to also just kick this can down the road until the next Ubuntu LTS sunsetting ;)

I'd appreciate it if we could merge this before tomorrow as the only reason I want this PR is to remove a misleading error messages in the OPTIMADE tutorials I'm giving!

[rartino]

Done!