We should replace `libsecp256k1` with `secp256k1` for better performance.

[PopcornPaws]

Description

Related substrate issue. This is not a burning issue for now, but apart from making the runtime more performant, it might mitigate compile issues emanating from libsecp256k1.

Solution

Change dependency in gn-common. This would also require a runtime upgrade because we use these deps indirectly in pallet-guild as well.