Update CHANGELOG

Add PR number.

Author: martincostello

CHANGELOG.md

@@ -211,10 +211,10 @@
 * Use 1.0.0-beta.2 of OpenTelemetry.Instrumentation.Cassandra
   ([#145](https://github.com/grafana/grafana-opentelemetry-dotnet/pull/145))
 * Use 3.22.0 of CassandraCSharpDriver
-  ([#TODO](https://github.com/grafana/grafana-opentelemetry-dotnet/pull/TODO))
+  ([#202](https://github.com/grafana/grafana-opentelemetry-dotnet/pull/202))
 * Enable tracing for Cassandra instrumentation (requires the
   `CassandraCSharpDriver.OpenTelemetry` NuGet package to be installed)
-  ([#TODO](https://github.com/grafana/grafana-opentelemetry-dotnet/pull/TODO))
+  ([#202](https://github.com/grafana/grafana-opentelemetry-dotnet/pull/202))
 
 ### Bug Fixes