[release] core-1.15.3 release updates#4166

martincostello merged 3 commits intomainopen-telemetry/opentelemetry-dotnet-contrib:mainfrom

otelbot/post-core-1.15.3-updateopen-telemetry/opentelemetry-dotnet-contrib:otelbot/post-core-1.15.3-updateCopy head branch name to clipboard