validateSync() returns invalid paths for nested errors in some cases where field names contain "." (period)

[ir0nCr055]

Describe the bug

The validateSync() function may return invalid error paths for some nested object field names containing "." (period).

Namely, the invalid paths returned are missing quotes.

To Reproduce

Given the following schema and object...

const schema = yup.object({
    "i.t._admin_name": yup.string().required("Enter a valid name"),
    "i.t._admin_email": yup
      .string()
      .required("Enter a valid email")
      .test("valid_email", "Email is invalid", (val) => {
        return false; // This test always fails to simplify the demonstration
      }),
  });

  // This example demonstrates the bug - we expect errors for both keys.
  const obj = {
    "i.t._admin_name": "",
    "i.t._admin_email": "invalid email",
  };

Evaluating schema.validateSync(obj, { abortEarly: false }) throws a validationError containing the following paths:

• ["i.t._admin_name"]
• [i.t._admin_email]

This test case is demonstrated here: https://codesandbox.io/p/devbox/yh65qd

Expected behavior

We'd expect the paths to be:

• ["i.t._admin_name"]
• ["i.t._admin_email"]

Platform

All tested browsers, versions including Chrome, Firefox.

Additional context

Bug discovered while integrating Yup with Formik and React.