turbo

84180e14 - feat: opt into breaking changes and pre-stable features early with `turbo.json` configuration (#10590)

feat: opt into breaking changes and pre-stable features early with `turbo.json` configuration (#10590) ### Description We want to smooth migration paths for users when we introduce functionality with breaking changes. This can be difficult with point-in-time majors that might force a user to make many breaking changes at once. Instead, we can introduce the concept of "future flags" to allow you to opt into breaking changes early. As a user, you get to have more control over when you adopt breaking changes. As a core team, we get more freedom to iterate, resulting in faster feedback cycles with users. This PR only introduces the flag to the parser, not adding any flags quite yet. This key is only allowed in root `turbo.json`s. ### Testing Instructions Added some tests. I also tried it out manually (and trivially). It worked how I'd hoped. --------- Co-authored-by: Chris Olszewski <chris.olszewski@vercel.com>