Sessions Cookies and Authentication: Update Rails Guide Reading Assignment

[SeanMero]

Update Assignment links due to changes in the Rails Guides

Because

The Rails Guides have updated, and some of our Assignment links are no longer pointing to the correct sections.

This PR

1. Change the link in part 4 of the Assignment to point to Section 7: Controller Callbacks
2. Change the link in part 5 to point to Section 11: HTTP Authentications in v7.2 of the Guide (as v8.0 of the Action Controller Overview does not have a similar section).

Issue

Closes #29279

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[JoshDevHub]

Thank you for fixing this!