Upgrade to DipDup v8

Our Tezos indexer is still running on DipDup v6, which is now end-of-life and no longer maintained. It’s very likely that our recent issues are caused by running v6 against a newer Tezos/TzKT environment.

Current Hypothesis

- #39 was only a temporary workaround to keep things running on v6; it looks like the upstream API may have now fully deprecated/support for the v6 path.

- Restarting the current version on v3-master doesn’t index all DAOs – only Temple DAO is being indexed; other DAOs never progress.

Why upgrading to v8 likely fixes this:

- EOL framework: DipDup 6.x no longer receives bug fixes or security patches; all active development is on 7.x/8.x.

- Tezos / TzKT drift: Tezos protocol and TzKT API have evolved (new operation types, updated models, etc.). v8 tracks these changes; v6 does not, which can cause runtime errors or silent mis-indexing.

**Important**: All of the above is an informed assumption based on behaviour we’re seeing. We need to confirm it by upgrading and checking logs/metrics.