Accessibility Failure: No persistent error in the subscribe form.

In the Jetpack subscribe form, the error disappears after a few seconds when the form is submitted with invalid data.

Steps to reproduce:

1. Go to any Jetpack email subscribe form.
2. Submit the form without any data or with an invalid email address.
3. An error alert is announced to the screen reader.
4. The error disappears, and moving to the field does not provide information about the error.

Expected Fix:

- When the form is submitted, the error must be in text.
- The error text must not disappear.
- The error needs to be associated with the form field using aria-describedby or aria-errormessage.

This error fails WCAG 2.2.1 timing adjustable.