Update changelog for v0.45.0 release (#1295)

Author: jeffreyc-splunk

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+## v0.45.0
+
+This Splunk OpenTelemetry Collector release includes changes from the [opentelemetry-collector v0.45.0](https://github.com/open-telemetry/opentelemetry-collector/releases/tag/v0.45.0) and the [opentelemetry-collector-contrib v0.45.1](https://github.com/open-telemetry/opentelemetry-collector-contrib/releases/tag/v0.45.1) releases.
+
 ### 💡 Enhancements 💡
 
 - Upgrade golang to 1.17.7 (#1294)