fix(gatsby-plugin-mdx): Replaces to-style with style-to-object

[pedrolamas]

Partially fixes #15058

Similar changes are required on Mdx and I've already submitted a PR for them (which once pushed, will require an update of the dependency in Gatsby)

[johno]

🙏

Thanks for taking this on and getting in a fix @pedrolamas!

[pedrolamas]

My other PR in @mdx-js/mdx to replace to-style with style-to-object has been merged and so this PR really needs to be merged as Gatsby MDX integration is currently broken!

Anyone using the latest @mdx-js/mdx package will see an error like this:

Error in "<root_folder>\node_modules\gatsby-mdx\gatsby-node.js": Cannot find module 'to-style'

This is because Gatsby is trying to use to-style but actually doesn't have it as a dependency anywhere on the project...

I made sure to add the style-to-object an camelcase-css dependencies as you can see here.

[pedrolamas]

I hope someone on @gatsbyjs/core is actually reading my message above and will be able to validate the current problem (and that this PR fixes it)

[johno]

Hmmm, are you using gatsby-plugin-mdx@1.0.20? It's a new release that just went out that should have the to-style dependency.

[pedrolamas]

Good point @johno!

For some weird reason, seems I was using the deprecated gatsby-mdx and not the correct gatsby-plugin-mdx... changing to the correct one fixed the dependency issue!

Given this, should I rebase my changes in this PR to ensure that to-style gets removed on merge?

[johno]

I merged in those other changes to your changes already, so we'll probably merge this in and release shortly!