Remove bench (because Björn is adding it)

Author: scottgerring

opentelemetry/Cargo.toml

@@ -57,11 +57,6 @@ harness = false
 name = "anyvalue"
 harness = false
 
-[[bench]]
-name = "context_attach"
-harness = false
-required-features = ["tracing"]
-
 [lib]
 bench = false