Remove Events tech debt from content-build

[jilladams]

Description

Events are now publishing to production via next-build rather than content-build. The content-build queries have been removed, but the metalsmith templates have not been and need to be, e.g site/layouts/event.drupal.liquid, etc.

Related thread: https://dsva.slack.com/archives/C03LFSPGV16/p1733871145447749?thread_ts=1733868069.562279&cid=C03LFSPGV16

Engineering notes / background

Need to remove any tech debt around Events in content-build, including:

• Liquid templates
• Any CSS styles that are no longer in use -- requires verification

Testing & QA

NOTE: Removing this tech debt has the potential to break things. These changes must be built in a Tugboat, and verified across products to ensure we are not removing anything that other products may be using that we are not aware of.

Acceptance criteria

• Events-related tech debt in content-build is removed including
  • Templates
  • Functions / helper stuff
  • CSS
• Changes have been reviewed in a Tugboat env, to confirm that other products are not affected by the changes.