Add December 23, 2025 post and update Advent of Cyber link

[mrbiggred]

Introduce a new post for the December 23, 2025 event focused on pair hacking for Advent of Cyber and update the link in the previous post. Unpin the last IRL event to reflect the current schedule.

[Copilot]

Pull request overview

This PR introduces a new blog post for a December 23, 2025 virtual event focused on collaborative hacking for TryHackMe's Advent of Cyber side quest, and unpins the previous in-person event announcement from December 11.

• Adds a new post announcing a virtual "Mob Hacking Advent of Cyber" session on December 23, 2025
• Unpins the December 11 IRL event announcement by removing the pin: true metadata field

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
docs/posts/2025/12/23/index.md	New post announcing December 23 virtual event for collaborative hacking on TryHackMe's Advent of Cyber
docs/posts/2025/12/11/index.md	Removes pin status from the December 11 IRL event announcement

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[Copilot]

The title says "Mob Hacking" but the content on line 8 describes the event as "pair hacking". These terms have different meanings - "mob programming" typically involves the entire team working together, while "pair programming/hacking" involves two people. The title and content should use consistent terminology that accurately describes the event format.

Suggested change

	title: "Mob Hacking Advent of Cyber"
	title: "Pair Hacking Advent of Cyber"

[Copilot]

The PR description states "update the link in the previous post" but the diff shows no link changes to docs/posts/2025/12/11/index.md - only the removal of the pin: true field. Either the PR description is inaccurate or the intended link update was not included in this change.