chore(Upgrade guide): removed verbiage on button aria-disabled

Author: Eric Olkowski

packages/documentation-site/patternfly-docs/content/get-started/upgrade.md

@@ -114,8 +114,6 @@ If you have previously implemented any breakpoint logic based on a pixel value,
 
 There are a few test failures that you're likely to encounter: 
 
-1. **Button:** Cannot find `aria-disabled`
-    - We changed button's `isDisabled` prop to assign a value for `disabled`, but none for `aria-disabled`. As a result, any test that looks for `aria-disabled` may fail.
 1. **Button:** Cannot find button attributes when using `byText`
     - There's a new wrapping `div` around text in buttons. The RTL `byText` query returns that wrapper instead of the button element itself, which is where button's attributes live. Instead of `byText`, use `byRole` and pass the button text to `name`. This will return the top-level button element.
 1. **Select (when using React Testing Library):** Cannot find `role`