Fix TypeAlias non-supported with py38 and py39 #3

Job	Run time
opentelemetry-api	35s
opentelemetry-getting-started	1m 4s
opentelemetry-opencensus-shim	44s
opentelemetry-opentracing-shim	44s
opentelemetry-proto	32s
opentelemetry-sdk	34s
opentelemetry-semantic-conventions	39s
opentelemetry-exporter-opencensus	44s
opentelemetry-exporter-otlp-combined	49s
opentelemetry-exporter-otlp-proto-common	48s
opentelemetry-exporter-otlp-proto-grpc	52s
opentelemetry-exporter-otlp-proto-http	49s
opentelemetry-exporter-prometheus	40s
opentelemetry-exporter-zipkin-combined	41s
opentelemetry-exporter-zipkin-proto-http	51s
opentelemetry-exporter-zipkin-json	41s
opentelemetry-propagator-b3	40s
opentelemetry-propagator-jaeger	37s
opentelemetry-test-utils	41s
	13m 45s

Provide feedback