Only print the path warnings once

We could reset and rerun it on server rebuilds, but that report needs a full build to make sense.

Also clean up the config vs flags in this area: Make all config settings match the flags e.g. `printPathWarnings`, but set up aliases for the
old.

Fixes #11187

commands/hugobuilder.go

@@ -43,7 +43,6 @@ import (
 	"github.com/gohugoio/hugo/hugolib/filesystems"
 	"github.com/gohugoio/hugo/livereload"
 	"github.com/gohugoio/hugo/resources/page"
-	"github.com/gohugoio/hugo/tpl"
 	"github.com/gohugoio/hugo/watcher"
 	"github.com/spf13/fsync"
 	"golang.org/x/sync/errgroup"
@@ -418,13 +417,6 @@ func (c *hugoBuilder) build() error {
 			return err
 		}
 
-		if c.r.printUnusedTemplates {
-			unusedTemplates := h.Tmpl().(tpl.UnusedTemplatesProvider).UnusedTemplates()
-			for _, unusedTemplate := range unusedTemplates {
-				c.r.logger.Warnf("Template %s is unused, source file %s", unusedTemplate.Name(), unusedTemplate.Filename())
-			}
-		}
-
 		h.PrintProcessingStats(os.Stdout)
 		c.r.Println()
 	}