CHANGELOG.md: add release heading for v0.52.2

This is an automated CL which updates the CHANGELOG.md.

Change-Id: Icca0f5104ca5196af33fd6c4cce23ca5186b55d0
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/739240
Auto-Submit: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Madeline Kalil <mkalil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: gopherbot

CHANGELOG.md

@@ -5,6 +5,13 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ## Unreleased
 
+## v0.52.2
+
+Date: 2026-01-26
+
+**Full Changelog**: https://github.com/golang/vscode-go/compare/v0.52.1...v0.52.2
+**Milestone**: https://github.com/golang/vscode-go/issues?q=milestone%3Av0.52.2
+
 ## v0.53.0 (prerelease)
 
 Date: 2025-12-18