Update OTLP proto version to 1.1.0 #4033

Job	Run time
non-default-examples (opentelemetry-otlp/examples/external-otlp-grpcio-async-std)	5m 6s
non-default-examples (opentelemetry-otlp/examples/basic-otlp)	46s
docs	5m 44s
cargo-deny	31s
external-types (opentelemetry)	1m 5s
lint	20m 14s
msrv	3m 46s
external-types (opentelemetry-sdk)	1m 15s
coverage	8m 18s
test (stable)	16m 3s
test (beta)	15m 55s
	1h 18m 43s

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