Eblurhash has been released to hex, we do not need to manually fetch
it from a git repository anymore.
The rest of the diffs have been generated by mix2nix.
A minor bug in mix2nix forced us to manually alter the base64url
dependency. The bug was already fixed upstream and should be resolved
for us once mix2nix branches off a new release. See
https://github.com/ydlr/mix2nix/issues/11 for more infos.
Release notes: https://pleroma.social/announcements/2021/08/08/pleroma-major-release-2-4-0/
