Deprecate site.Language.Params and some other fixes

Updates #10947

hugolib/hugo_sites_build.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/gohugoio/hugo/langs"
 	"github.com/gohugoio/hugo/publisher"
 
 	"github.com/gohugoio/hugo/hugofs"
@@ -40,6 +41,11 @@ import (
 	"github.com/gohugoio/hugo/helpers"
 )
 
+func init() {
+	// To avoid circular dependencies, we set this here.
+	langs.DeprecationFunc = helpers.Deprecated
+}
+
 // Build builds all sites. If filesystem events are provided,
 // this is considered to be a potential partial rebuild.
 func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {