Use required version of federation coreSpec rather than latest

[clenfest]

Important points

• We get the the version of any core feature implied by that version of federation, unless there has been a major version bump
• If there has been a major version bump of the core spec, we get the minimum required version that matches the major version of latest

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🦋 Changeset detected

Latest commit: cfdd354

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 7 packages

Name	Type
@apollo/composition	Minor
@apollo/federation-internals	Minor
@apollo/gateway	Minor
@apollo/query-planner	Minor
@apollo/query-graphs	Minor
@apollo/subgraph	Minor
apollo-federation-integration-testsuite	Minor

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[clenfest]

Note to reviewers: I'm slightly unsure on two points.

1. federation.ts still uses latest() for the tag/link/federation specs. I think this is ok, in almost all cases, since as far as I can tell Merger doesn't use a FederationBlueprint for the schema. However,
2. Will this cause a problem with extractSubgraphFromSupergraph? I think it may, but I may have to give this some more thought.

[trevor-scheer]

Just a few minor suggestions.

Can we add some integration-ish tests for the composeServices fn which show various versions being used and the resulting supergraph?

Needs a changeset as well.

[clenfest]

So the reason I didn't put any tests into composeServices is that there isn't really anything to test just yet. Since we are saying that this isn't relevant for older versions, We'll always get the latest versions of joinSpec, etc. for now, and it won't become relevant until there is a new version of one of them.