Pre-release: Update version to 0.8.0#280

ezhang6811 merged 2 commits intorelease/v0.8.xaws-observability/aws-otel-js-instrumentation:release/v0.8.xfrom

v0.8.0_releaseaws-observability/aws-otel-js-instrumentation:v0.8.0_releaseCopy head branch name to clipboard