feat: allow OpenTelemetry context access from SpanRef#234

mladedav merged 2 commits intotokio-rs:v0.1.xtokio-rs/tracing-opentelemetry:v0.1.xfrom

bantonsson:ban/spanrefext-for-otel-contextbantonsson/tracing-opentelemetry:ban/spanrefext-for-otel-contextCopy head branch name to clipboard