treewide: use $out instead of $bin with buildGoPackage

pkgs/applications/networking/cluster/terraform/default.nix

@@ -26,7 +26,7 @@ let
 
       postInstall = ''
         # remove all plugins, they are part of the main binary now
-        for i in $bin/bin/*; do
+        for i in $out/bin/*; do
           if [[ $(basename $i) != terraform ]]; then
             rm "$i"
           fi
@@ -88,7 +88,7 @@ let
 
             buildCommand = ''
               mkdir -p $out/bin/
-              makeWrapper "${terraform.bin}/bin/terraform" "$out/bin/terraform" \
+              makeWrapper "${terraform}/bin/terraform" "$out/bin/terraform" \
                 --set NIX_TERRAFORM_PLUGIN_DIR "${
                   buildEnv {
                     name = "tf-plugin-env";