Update CHANGELOG

Author: Andrew Hall

CHANGELOG.md

@@ -4,7 +4,7 @@
 - Debug from .csproj and .sln [#5876](https://github.com/dotnet/vscode-csharp/issues/5876)
 
 # 2.55.x
-* Update Razor to 9.0.0-preview.24557.10 (PR: []())
+* Update Razor to 9.0.0-preview.24557.10 (PR: [#7757](https://github.com/dotnet/vscode-csharp/pull/7757))
   * Update VSTelemetryAPI version (#11181) (PR: [#11181](https://github.com/dotnet/razor/pull/11181))
 * Update Roslyn to 4.13.0-2.24531.3 (PR: [#7722](https://github.com/dotnet/vscode-csharp/pull/7722))
   * Proffer project system query service (PR: [#75682](https://github.com/dotnet/roslyn/pull/75682))