docs: Add changelog entry for CMake FetchContent support

- Document new CMake FetchContent functionality in CHANGELOG.md
- References PR #104 for automated dependency updates
- Follows existing changelog format and conventions

Author: vaind

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features
 
 - Add Proguard artifact endpoint for Android builds in sentry-server ([#100](https://github.com/getsentry/github-workflows/pull/100))
+- Updater - Add CMake FetchContent support for automated dependency updates ([#104](https://github.com/getsentry/github-workflows/pull/104))
 
 ### Security