Replace the danger-callout with help text
## Problem to solve
Older `danger-callout` components are being used to share constraints with users for **personal access tokens** and **ssh key** expiration dates, which do not match guidelines in Pajamas.
| Personal access tokens | SSH keys |
| ------ | ------ |
|  |  |
## Proposal
- Remove the `danger-callout` and replace with help text.
- Update the help and description text
- The date picker should prevent picking invalid dates. Should a user input an invalid date, they should get an error message
| Personal access tokens | SSH keys |
| ------ | ------ |
|  ||
issue