fix(docker/builders): fixed libelf-dev and dwarves incompatibilities in debian backports.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

Author: FedeDP

docker/builders/builder-any-x86_64_gcc8.0.0_gcc6.0.0_gcc5.0.0_gcc4.9.0_gcc4.8.0.Dockerfile

@@ -1,11 +1,10 @@
-FROM debian:buster
+FROM debian:buster-backports
 
 LABEL maintainer="cncf-falco-dev@lists.cncf.io"
 
 ARG TARGETARCH
 
 RUN cp /etc/skel/.bashrc /root && cp /etc/skel/.profile /root
-RUN echo 'deb http://deb.debian.org/debian buster-backports main' >>/etc/apt/sources.list
 
 RUN apt-get update \
 	&& apt-get install -y --no-install-recommends \
@@ -21,7 +20,7 @@ RUN apt-get update \
 	gcc \
 	jq \
 	libc6-dev \
-	libelf-dev \
+	libelf-dev/buster-backports \
 	netcat \
 	xz-utils \
 	rpm2cpio \