How to silence "Configuration property rebalance_cb is a consumer property and will be ignored by this producer instance"

Question

I am running a docker container with alpine, nginx and php. On it I have a symfony application running, which is using "flix-tech/avro-serde-php" and "koco/messenger-kafka". My Docker file looks like this:

[...]

ARG LIBRDKAFKA_GIT_SHA1=1f7417d4796e036b8c19f17373f8290ff5c7561f
RUN apk add --update --no-cache alpine-sdk bash python3 autoconf openssl-dev \
  && git clone -o ${LIBRDKAFKA_GIT_SHA1} https://github.com/edenhill/librdkafka.git /tmp/librdkafka \
  && cd /tmp/librdkafka/  \
  && ./configure \
  && make  \
  && make install

# php-rdkafka should be compiled using the same php module as result we are passing
# --with-php-config /usr/local/bin/php-config
ARG PHPCONF_PATH=/usr/local/etc/php/php.ini.d
ARG RDKAFKA_PHP_GIT_SHA1=abd6b6add8e0b983c27245a59981a9a4b5389139
RUN apk add --update --no-cache pcre-dev \
    && pecl install rdkafka

[...]

That is all fine and dandy. However the container is only sending data to kafka, since it is a producer. It isn't a consumer. So when the data is sent to kafka the following bash entry is generated: Configuration property rebalance_cb is a consumer property and will be ignored by this producer instance which then after some steps end up in datadog, my logging system as an error, which it isn't.

So my question is how I can get rid of this message? Is there a configuration setting, telling the system that it is only a producer? I didn't find the property rebalance_cb anywhere in my project so it is neither part of my code nor of the used libraries. I guess it is part of the compiled librdkafka.

Is there maybe an option to configure the build so that it is only a producer? Or a php.ini setting? I couldn't find anything so far.

Or is there an option for a monolog configuration, which silences such messages?