Switch bellpepper dependency (#273)

* chore: Update bellpepper dependencies and test tolerances

- Updated `bellpepper-core` dependency to a released version for stability and reliability
- Kept `bellpepper` dependency source to promote code consistency, utilizing the `dev` branch from the new repository.

* point the bellpepper dependency back to lurk-lab@dev

Cargo.toml

@@ -85,7 +85,7 @@ members = [
 
 # Dependencies that should be kept in sync through the whole workspace
 [workspace.dependencies]
-bellpepper-core = { git = "https://github.com/lurk-lab/bellpepper", branch = "dev", default-features = false }
+bellpepper-core = { version = "0.4.0", default-features = false }
 bellpepper = { git = "https://github.com/lurk-lab/bellpepper", branch = "dev", default-features = false }
 blake2s_simd = "1.0.1"
 blstrs = { version = "0.7.0" }