## Issue Addressed
This is related to #1926 and #1712.
## Proposed Changes
This PR adds a test that make sure that the used dependencies can be vendored.
Being able to vendor the dependencies is important for archival and repdroducibility purpose.
It's also required to package lighthouse for some Linux distributions. Specifically [NixOS](https://nixos.org/) and [Yocto](https://www.yoctoproject.org/).
## Additional Info
This PR only adds the test, it doesn't clean up the dependencies yet. That's why it is in draft.
## Issue Addressed
None
## Proposed Changes
Adds support for downloading the deposit contract from a different location
by setting the environement variables `LIGHTHOUSE_DEPOSIT_CONTRACT_SPEC_URL`
and `LIGHTHOUSE_DEPOSIT_CONTRACT_TESTNET_URL`.
It also adds support to fetch the content from a local file:// URL.
This allows pre fetching to build in an environment without network access.
## Additional Info
Being able to build without network access is required to package the application for https://nixos.org/. But I imagine it might be useful for other distributions too.
Pascal Bach