Previously two cryptography libraries were linked into Lix: OpenSSL used for hashing and (in usual configurations) indirectly via curl for TLS, and Sodium used only for handling the Ed25519 path info signatures. The latter is functionally redundant since OpenSSL supports the same use case as well. Reimplement the Ed25519 handling using OpenSSL and drop Sodium. Fixes: https://git.lix.systems/lix-project/lix/issues/969 Change-Id: I6a6a696456b9d3ad7fdc2bf9b0759836a6247a38