Fix types for fetch

EAS GraphQL API wraps response in `data` while metadata doesn't.
- [ ] Update `utils/fetchAttestations` with the wrapping data (`r.data.data...`)
https://github.com/gitcoinco/easy-retro-pgf/blob/fb4e97177b3e311881c830b769f3206ffa9b417c/src/utils/fetchAttestations.ts#L66-L80

- [ ] Update `utils/fetch` to `return (await r.json()) as T`

- https://github.com/gitcoinco/easy-retro-pgf/blob/main/src/utils/fetch.ts#L20

Start with src/utils/fetchAttestations.ts around lines 66-80 and src/utils/fetch.ts around line 20. Check the different EAS GraphQL and metadata response shapes, then confirm the requested response wrapping and generic JSON cast are reflected in both utilities. Done means the two checklist items are completed without changing unrelated fetch behavior.

Written by the indexing model from the issue text.