Change some changeset bump types and do a few changeset cleanups

[Andarist]

closes #1471

I've promoted @emotion/is-prop-valid & @emotion/serialize to v1. While this isn't technically necessary and doesn't really help #1471 anyhow as any, previously, minor bump will just have to be a major bump now so nothing changes in regards to possibly duplicated modules. However, I kinda have started to consider 0.x versions harmful - they require a slightly different mindset and when managing a monorepo I just don't want to focus on that.

Changesets also do not differentiate them - so while major bumping you get a nice helpful message about what should be put into a changeset, but when minor bumping 0.x (which is a similar situation) you don't get any such message.

It also makes it less apparent that you might end up with weird situations when managing 2 release lines (master & next) such as the one reported here: #1974 . Making those packages v1+ doesn't, of course, solve this problem entirely - but I feel one is way more vigilant about cases like this when working with >=1.0 packages and thus it makes it harder to run into such problems.

I haven't touched some packages that are still at 0.x stage as there is only a low chance for them to ever be upgraded - like @emotion/memoize. And even if we decide to upgrade them, for whatever reason, then it won't really matter if we upgrade them with a minor or with a major bump, both mean a breaking change for them, so I have concluded that it's not worth creating weird changelog entries right now just for a sake of upgrading them.

Also - I've cleaned up a few changeset files just a little bit. Just some random things I've spotted when reviewing existing changesets. More cleanups will be required before releasing v11.

[changeset-bot]

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