Language versioned changes on breaking changes page

[MaryaBelanger]

This CL updating the breaking change definition in the sdk specifically says that language versioned changes are not breaking changes, so we have to update this:

This page includes the following types of breaking changes:
...
- Language versioned:

I know we do want to keep labeling language versioned changes on that page, though, so maybe it's a matter of moving that label definition out of that list and saying something like "Language versioned changes are not breaking changes, but are also labeled on this page"

cc @leafpetersen