fix: delete instance data and remove legacy shared workspace support

internal/api/admission.go

@@ -27,11 +27,7 @@ func defaultAdmission(version, recipe, platform string) string {
 	return "existing_only"
 }
 func supportedLayout(recipe string) bool {
-	switch recipe {
-	case "3", "4", "5", "6", "7":
-		return true
-	}
-	return false
+	return recipe == imageRecipeRev
 }
 func positiveAdmission(state string) bool { return state == "recommended" || state == "compatible" }