Update ARIA Practices link in PR template to the latest version (#5816)

Co-authored-by: Robert Snow <[email protected]>

Author: ryo-manba

.github/PULL_REQUEST_TEMPLATE.md

@@ -7,7 +7,7 @@ Closes <!-- Github issue # here -->
 - [ ] Added/updated unit tests and storybook for this change (for new code or code which already has tests).
 - [ ] Filled out test instructions.
 - [ ] Updated documentation (if it already exists for this component).
-- [ ] Looked at the Accessibility Practices for this feature - [Aria Practices](https://www.w3.org/TR/wai-aria-practices-1.1/)
+- [ ] Looked at the Accessibility Practices for this feature - [Aria Practices](https://www.w3.org/WAI/ARIA/apg/)
 
 ## 📝 Test Instructions: