fix: ensure libp2p fork is used in crates.io (#928)

Description
---
Specify libp2p fork as a dependency rather than a patch
Use workspace deps for libp2p_peersync behaviour

Motivation and Context
---
When building from outside the repo, patches are not used. For now, it's
just easier to specify the git fork as a direct dependency rather than
patching crates.io.

ALso looks like the zeroize issue for liblmdb-sys is resolved, so the
patch is removed

How Has This Been Tested?
---
Lints/CI

What process can a PR reviewer use to test or verify this change?
---
CI


Breaking Changes
---

- [x] None
- [ ] Requires data directory to be deleted
- [ ] Other - Please specify