Add 1.129 release date to changelog (#904)

Author: vezwork

apps/vscode/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## 1.129.0 (Unreleased)
+## 1.129.0 (Release on 2026-01-29)
 
 - Fixed Copilot completions in `.qmd` documents (<https://github.com/quarto-dev/quarto/pull/887>).
 - Fixed a bug where the `autoDetectColorScheme` setting could cause equation previews to have a dark text on dark background and vice versa (<https://github.com/quarto-dev/quarto/pull/864>).