Require additional user confirmation for making repo private (#36959)

To align with how GitHub requires additional explicit user interaction
to make a repo private, including informing them of implications on what
happens if they do.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/test/utils.go

@@ -45,6 +45,14 @@ func ParseJSONError(buf []byte) (ret struct {
 	return ret
 }
 
+func ParseJSONRedirect(buf []byte) (ret struct {
+	Redirect string `json:"redirect"`
+},
+) {
+	_ = json.Unmarshal(buf, &ret)
+	return ret
+}
+
 func IsNormalPageCompleted(s string) bool {
 	return strings.Contains(s, `<footer class="page-footer"`) && strings.Contains(s, `</html>`)
 }