Consolidate all hashing to the common/hashing package

And remove now unsued hashing funcs.

resources/image.go

@@ -29,9 +29,9 @@ import (
 	color_extractor "github.com/marekm4/color-extractor"
 
 	"github.com/gohugoio/hugo/cache/filecache"
+	"github.com/gohugoio/hugo/common/hashing"
 	"github.com/gohugoio/hugo/common/hstrings"
 	"github.com/gohugoio/hugo/common/paths"
-	"github.com/gohugoio/hugo/identity"
 
 	"github.com/disintegration/gift"
 
@@ -40,7 +40,6 @@ import (
 
 	"github.com/gohugoio/hugo/resources/resource"
 
-	"github.com/gohugoio/hugo/helpers"
 	"github.com/gohugoio/hugo/resources/images"
 
 	// Blind import for image.Decode
@@ -274,7 +273,7 @@ func (i *imageResource) Filter(filters ...any) (images.ImageResource, error) {
 	}
 
 	conf.Action = "filter"
-	conf.Key = identity.HashString(gfilters)
+	conf.Key = hashing.HashString(gfilters)
 	conf.TargetFormat = targetFormat
 	if conf.TargetFormat == 0 {
 		conf.TargetFormat = i.Format
@@ -481,7 +480,7 @@ func (i *imageResource) getImageMetaCacheTargetPath() string {
 	df := i.getResourcePaths()
 	p1, _ := paths.FileAndExt(df.File)
 	h := i.hash()
-	idStr := identity.HashString(h, i.size(), imageMetaVersionNumber, cfgHash)
+	idStr := hashing.HashString(h, i.size(), imageMetaVersionNumber, cfgHash)
 	df.File = fmt.Sprintf("%s_%s.json", p1, idStr)
 	return df.TargetPath()
 }
@@ -504,7 +503,7 @@ func (i *imageResource) relTargetPathFromConfig(conf images.ImageConfig) interna
 	// can easily be too long to read, and maybe even too long
 	// for the different OSes to handle.
 	if len(p1)+len(idStr)+len(p2) > md5Threshold {
-		key = helpers.MD5String(p1 + key + p2)
+		key = hashing.MD5FromStringHexEncoded(p1 + key + p2)
 		huIdx := strings.Index(p1, "_hu")
 		if huIdx != -1 {
 			p1 = p1[:huIdx]