Playback 2024: Remove duration from ending story in Playback 2024

[bjtitus]

📘 Part of: #2250

Fixes #2417

Before	After
Simulator.Screen.Recording.-.iPhone.16.-.2024-11-13.at.19.47.00.mp4	Simulator.Screen.Recording.-.iPhone.16.-.2024-11-13.at.19.45.30.mp4

To test

• Tap through the Playback 2024 stories
• On the final story with the "Thanks" scrolling text, verify that the progress bar doesn't animate.

Checklist

• I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• I have considered adding unit tests for my changes.
• I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 7.77 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by 🚫 Danger

[SergioEstevao]