fix(nix): prebuild host package for web build (#2280)

Author: mrcfps

nix/package-web.nix

@@ -57,6 +57,7 @@ in
       runHook preBuild
       for target in \
         packages/contracts \
+        packages/host \
         packages/sidecar-proto \
         packages/sidecar \
         packages/platform