Do not install recommended packages

In general it is better to specify our exact dependencies instead of
relying on recommended packages to install them.

build.sh

@@ -19,7 +19,7 @@ export DEBIAN_FRONTEND=noninteractive
 # Install required build dependencies
 apt-get update
 apt-get -y upgrade
-apt-get install -y \
+apt-get install -y --no-install-recommends \
   autotools-dev \
   build-essential \
   curl \

upload.sh

@@ -4,7 +4,7 @@ set -o pipefail
 
 # Install SSH client
 apt-get update
-apt-get install -y openssh-client
+apt-get install -y --no-install-recommends openssh-client
 
 # Create SSH configuration
 (