Update manual app because OTel SDK no dep on OTel instrumentation pkg (#41)

Author: NathanielRN

integration-test-apps/manual-instrumentation/flask/requirements.txt

@@ -5,10 +5,10 @@ flask
 ./opentelemetry-python-core/opentelemetry-semantic-conventions
 ./opentelemetry-python-core/opentelemetry-proto
 ./opentelemetry-python-core/opentelemetry-api
-./opentelemetry-python-core/opentelemetry-instrumentation
 ./opentelemetry-python-core/opentelemetry-sdk
 ./opentelemetry-python-core/exporter/opentelemetry-exporter-otlp-proto-grpc
 ./opentelemetry-python-core/exporter/opentelemetry-exporter-otlp
+./opentelemetry-python-contrib/opentelemetry-instrumentation
 ./opentelemetry-python-contrib/sdk-extension/opentelemetry-sdk-extension-aws
 ./opentelemetry-python-contrib/propagator/opentelemetry-propagator-aws-xray
 ./opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-botocore