feat: require launch measurements for SEV-enabled subnets

[r-birkner]

An SEV-enabled subnet may now only run a GuestOS version that has guest_launch_measurements. This is enforced as a registry invariant, so any mutation that would leave an SEV-enabled subnet on a version without launch measurements is rejected.

Note: A CloudEngine may leave replica_version_id blank, in which case it runs the versions of the StandardEngineReplicaVersionRecord.

[r-birkner]

Note for Reviewer @daniel-wong-dfinity-org: There is also this PR that addresses the same issue in a different place. By adding this one, we are protected at the version election and the deployment. But we can also drop this if you think it is not needed.

[github-actions]

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[zeropath-ai]

✅ No security or compliance issues detected. Reviewed everything up to 70740be.

Security Overview

• 🔎 Scanned files: 6 changed file(s)
• 🔗 Scan Link: https://zeropath.com/app/repositories/f975f1a5-0a47-4a3b-b7f0-a55609e90390?scanId=ba6cd1da-4896-4f18-a936-15934deb4da0&codeScanTypes=PrScan&tab=issues

Detected Code Changes

Change Type

Relevant files

Enhancement

► rs/registry/canister/src/common/test_helpers.rs     Add helper to insert guest launch measurements into replica version ► rs/registry/canister/src/invariants/replica_version.rs     Make get_all_standard_engine_replica_versions public ► rs/registry/canister/src/invariants/subnet.rs     Update imports and integrate SEV launch measurement checks into invariants ► rs/registry/canister/src/invariants/subnet/tests.rs     Add tests for SEV launch measurements and related scenarios ► rs/registry/canister/src/mutations/do_update_subnet.rs     Update test helpers usage to include launch measurement helper ► rs/registry/canister/unreleased_changelog.md     Document SEV subnet launch measurement invariant changes