Update comment

Signed-off-by: Jason Parraga <sovietaced@gmail.com>

Author: Sovietaced

tox.ini

@@ -308,7 +308,7 @@ commands_pre =
               -e {toxinidir}/opentelemetry-semantic-conventions \
               -e {toxinidir}/opentelemetry-sdk \
               -e {toxinidir}/tests/opentelemetry-test-utils \
-  ; opencensus exporter does not work with protobuf 4
+  ; opencensus exporter does not work with protobuf 4 and protobuf 5
   proto3:     -e {toxinidir}/exporter/opentelemetry-exporter-opencensus \
               -e {toxinidir}/opentelemetry-proto \
               -e {toxinidir}/exporter/opentelemetry-exporter-otlp-proto-common \