remove subpath feature validation failure

pkg/apis/core/validation/validation.go

@@ -2299,12 +2299,8 @@ func ValidateVolumeMounts(mounts []core.VolumeMount, voldevices map[string]strin
 		}
 
 		if len(mnt.SubPath) > 0 {
-			if !utilfeature.DefaultFeatureGate.Enabled(features.VolumeSubpath) {
-				allErrs = append(allErrs, field.Forbidden(fldPath.Child("subPath"), "subPath is disabled by feature-gate"))
-			} else {
 			allErrs = append(allErrs, validateLocalDescendingPath(mnt.SubPath, fldPath.Child("subPath"))...)
 		}
-		}
 
 		if mnt.MountPropagation != nil {
 			allErrs = append(allErrs, validateMountPropagation(mnt.MountPropagation, container, fldPath.Child("mountPropagation"))...)

pkg/apis/core/validation/validation_test.go

@@ -4931,7 +4931,7 @@ func TestValidateDisabledSubpath(t *testing.T) {
 					SubPath:   "baz",
 				},
 			},
-			true,
+			false, // validation should not fail, dropping the field is handled in PrepareForCreate/PrepareForUpdate
 		},
 	}