Remove Advent calendar from README (#36777)

* Remove Advent calendar from README

* Update hero image

* Delete doc/images/overview/PT_holiday_hero_image.png

README.md

@@ -1,6 +1,6 @@
 # Microsoft PowerToys
 
-![Hero image for Microsoft PowerToys](doc/images/overview/PT_holiday_hero_image.png)
+![Hero image for Microsoft PowerToys](doc/images/overview/PT_hero_image.png)
 
 [How to use PowerToys][usingPowerToys-docs-link] | [Downloads & Release notes][github-release-link] | [Contributing to PowerToys](#contributing) | [What's Happening](#whats-happening) | [Roadmap](#powertoys-roadmap)
 
@@ -20,12 +20,6 @@ Microsoft PowerToys is a set of utilities for power users to tune and streamline
 | [Registry Preview](https://aka.ms/PowerToysOverview_RegistryPreview) | [Screen Ruler](https://aka.ms/PowerToysOverview_ScreenRuler) | [Shortcut Guide](https://aka.ms/PowerToysOverview_ShortcutGuide) |
 | [Text Extractor](https://aka.ms/PowerToysOverview_TextExtractor) | [Video Conference Mute](https://aka.ms/PowerToysOverview_VideoConference) | [Workspaces](https://aka.ms/PowerToysOverview_Workspaces) |
 
-## 🎁⭐ PowerToys Advent calendar ⭐🎁
-
-We will be highlighting a cool utility each day for 24 days in December! To follow along, check out these threads:
-- https://bsky.app/profile/kaylacinnamon.bsky.social/post/3lcb7iljxck2o
-- https://x.com/cinnamon_msft/status/1863284610773246257
-
 ## Installing and running Microsoft PowerToys
 
 ### Requirements