Extend `End of Life` date.

[edthedev]

Context

As our support for AWS CLI V2 nears completion, we need to remember to move our standard End of Life date in README.md forward to account for the extended life that our new compatibility will add.

It actually looks like we don't have that date added to README yet, so let's get it added.

Tasks

• [ ] re-calculate an end-of-life prediction based on current supported versions of Python and AWS CLI. I realize this may involve guesswork for AWS CLI, or a disclaimer, and update in the docs that appear on PyPI.
• [ ] link or add the end-of-life language to README.md per our guide here: https://answers.uillinois.edu/illinois/109544

I'm inclined to include the fact that we effectively support AWS CLI V2 in this date calculation, even though it's not fully released. We know it works.

[edthedev]

The end of life statement is on test pyPI, but not production. (Probably a cut-and-paste error when we refactored the docs.)

"The expected End-of-Life and End-of-Support date of this version is October 2028, the same as its primary dependencies: the AWS CLI and Python V3.12."

https://test.pypi.org/project/awscli-login/

https://pypi.org/project/awscli-login/

[edthedev]

This should happen after #218, since it will bump the end-on-life date further into the future.