Changes include:
- Removing all submodules from vendor folder.
- Updating sds.nimble with required depndencies.
- Generating a nimble.lock file using Nimble.
- Updated Nim code to reference depndencies correctly.
- Added nix/deps.nix fixed output derivation that calls Nimble.
- Updated nixpkgs to use 25.11 commit which provides Nimbe 0.20.1.
- Disabled Nix Android builds on MacOS due to Nimble segfault.
Signed-off-by: Jakub Sokołowski <jakub@status.im>
