CHANGELOG.md: add release heading for v0.47.3

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

Change-Id: Ibab5c79cc1b9778491a7829e0296d8d754f65b64
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/679215
Auto-Submit: Gopher Robot <[email protected]>
kokoro-CI: kokoro <[email protected]>
Reviewed-by: Madeline Kalil <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Hongxiang Jiang <[email protected]>

Author: gopherbot

CHANGELOG.md

@@ -23,6 +23,15 @@ error during command execution when the command result did not include a token.
 ([Issue 3698](https://github.com/golang/vscode-go/issues/3698))
 * Addressed an issue that broke the `Debug Subtest At Cursor` command. ([Issue 3718](https://github.com/golang/vscode-go/issues/3718))
 
+## v0.47.3 (prerelease)
+
+Date: 2025-06-05
+
+This is the [pre-release version](https://code.visualstudio.com/api/working-with-extensions/publishing-extension#prerelease-extensions) of v0.48.
+
+**Full Changelog**: https://github.com/golang/vscode-go/compare/v0.46.0-rc.1...v0.47.3
+**Milestone**: https://github.com/golang/vscode-go/issues?q=milestone%3Av0.48.0
+
 ## v0.47.2 (prerelease)
 
 Date: 2025-04-15