fix(sdk-trace-base): always wait on pending export in SimpleSpanProcessor#5303

pichlermarc merged 12 commits into

open-telemetry:mainopen-telemetry/opentelemetry-js:mainfrom

anuraaga:simplespanprocessor-waitalwaysanuraaga/opentelemetry-js:simplespanprocessor-waitalwaysCopy head branch name to clipboard