Add back in libsodium.

Author: angerman

test/cabal.project.local

@@ -27,6 +27,15 @@ repository ghcjs-overlay
   key-threshold: 0
   --sha256: sha256-mZT7c+xR5cUTjLdCqOxpprjYL3kr/+9rmumtXvWAQlM=
 
+-- This is needed because nixpkgs has 1.0.19, and libsodium has
+-- too tight bounds <1.0.18.
+if !os(ghcjs)
+  source-repository-package
+    type: git
+    location: https://github.com/hamishmack/hs-libsodium.git
+    tag: c094f210f3bd34d97204451ea57855a5d17e2086
+    --sha256: sha256-6iCKvdLdjwg2jcoWMEj3qcFTvKe3P4BYxgKeXY3QwRM=
+
 if !impl(ghc>=9.11) && !os(ghcjs)
   active-repositories: hackage.haskell.org