update VERSION and LATEST_RELEASE after releasing 0.8.0

[mblaze-da]

[ci]

Pull Request Checklist

Cluster Testing

• If a cluster test is required, comment /cluster_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
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• If a logical synchronizer upgrade test is required (from canton-3.5), comment /lsu_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.

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[martinflorian-da]

🎉