add library until better solution

vendor/github.com/stretchr/testify/assert/assertion_compare_legacy.go

@@ -0,0 +1,16 @@
+//go:build !go1.17
+// +build !go1.17
+
+// TODO: once support for Go 1.16 is dropped, this file can be
+//       merged/removed with assertion_compare_go1.17_test.go and
+//       assertion_compare_can_convert.go
+
+package assert
+
+import "reflect"
+
+// Older versions of Go does not have the reflect.Value.CanConvert
+// method.
+func canConvert(value reflect.Value, to reflect.Type) bool {
+	return false
+}