Update note to past tense in multiple articles

[nguyenalex836]

Code of Conduct

• I have read and agree to the GitHub Docs project's Code of Conduct

What article on docs.github.com is affected?

https://docs.github.com/en/authentication/securing-your-account-with-two-factor-authentication-2fa/about-mandatory-two-factor-authentication

https://docs.github.com/en/authentication/securing-your-account-with-two-factor-authentication-2fa/disabling-two-factor-authentication-for-your-personal-account

What part(s) of the article would you like to see updated?

As of March 2023, GitHub began to require all users who contribute code on GitHub.com to enable one or more forms of two-factor authentication (2FA). If you were in an eligible group, you would have received a notification email when that group was selected for enrollment, marking the beginning of a 45-day 2FA enrollment period, and you would have seen banners asking you to enroll in 2FA on GitHub.com. If you didn't receive a notification, then you were not part of a group required to enable 2FA, though we strongly recommend it.

This note, present in both linked articles, needs to be updated to past tense

Additional information

No response