Revert "Update package.json peerDependencies (#6594)"

[hwillson]

This reverts commit 831b7ab.

We rushed this in just before the AC3 launch without fully thinking through the consequences. From #6594 (comment):

I think you ought to reconsider this change. See this explanation. It's also been rejected in other prominent repos like React.

tl;dr: it's likely that at some point in the future, a new major version of at least one of these peer dependencies will be released that isn't compatible with Apollo Client's use of it. This will cause Apollo Client to break without warning if the consumer upgrades this dependency. It's essentially the same reason why one wouldn't want to use >= for regular dependencies.

Thanks for catching this @billyjanitsch!

[benjamn]

LGTM