ee: add Join for go 1.20

Author: ImSingee

ee/go120.go

@@ -0,0 +1,20 @@
+//go:build go1.20
+// +build go1.20
+
+package ee
+
+import (
+	stderrors "errors"
+)
+
+// Join returns an error that wraps the given errors.
+// Any nil error values are discarded.
+// Join returns nil if every value in errs is nil.
+// The error formats as the concatenation of the strings obtained
+// by calling the Error method of each element of errs, with a newline
+// between each string.
+//
+// A non-nil error returned by Join implements the Unwrap() []error method.
+func Join(errs ...error) error {
+	return stderrors.Join(errs...)
+}