drop support for legacy patches (#4911)

* drop support for legacy patches

* fix CI

api/types/fix.go

@@ -5,8 +5,6 @@ package types
 
 import (
 	"regexp"
-
-	"sigs.k8s.io/yaml"
 )
 
 // FixKustomizationPreUnmarshalling modifies the raw data
@@ -20,35 +18,5 @@ func FixKustomizationPreUnmarshalling(data []byte) ([]byte, error) {
 		pattern := regexp.MustCompile(oldname)
 		data = pattern.ReplaceAll(data, []byte(newname))
 	}
-	doLegacy, err := useLegacyPatch(data)
-	if err != nil {
-		return nil, err
-	}
-	if doLegacy {
-		pattern := regexp.MustCompile("patches:")
-		data = pattern.ReplaceAll(data, []byte("patchesStrategicMerge:"))
-	}
 	return data, nil
 }
-
-func useLegacyPatch(data []byte) (bool, error) {
-	found := false
-	var object map[string]interface{}
-	err := yaml.Unmarshal(data, &object)
-	if err != nil {
-		return false, err
-	}
-	if rawPatches, ok := object["patches"]; ok {
-		patches, ok := rawPatches.([]interface{})
-		if !ok {
-			return false, err
-		}
-		for _, p := range patches {
-			_, ok := p.(string)
-			if ok {
-				found = true
-			}
-		}
-	}
-	return found, nil
-}