Cirrus CI: Add the binutils-dev package, Linux task

It is needed to build with --enable-instrument-functions
(make releasecheck).

Author: fxlb

.cirrus.yml

@@ -38,7 +38,7 @@ linux_task:
   script:
     - apt-get -qy update >/dev/null
     - apt-get -qy install autoconf make gcc libpcap-dev >/dev/null # for "./configure"
-    - apt-get -qy install cmake git >/dev/null # for "make releasecheck"
+    - apt-get -qy install cmake git binutils-dev >/dev/null # for "make releasecheck"
     - apt-get -qy install shellcheck >/dev/null
     - ./autogen.sh
     - ./configure --quiet # build the Makefile