feat(rpm-builder): add rpm-builder binary and fix PATh environment

installation-scripts/01-rustup.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -e
+
+curl --proto "=https" --tlsv1.2 -sSf https://sh.rustup.rs > /tmp/rustup.sh && \
+  chmod +x /tmp/rustup.sh && \
+  /tmp/rustup.sh -y && \
+  source ${HOME}/.cargo/env && \
+  rustup target add x86_64-unknown-linux-musl

installation-scripts/02-rpm-builder.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e
+
+VERSION=v0.3.1
+TMP_DIR=$(mktemp -d)
+
+git clone --branch ${VERSION} https://github.com/Richterrettich/rpm-builder.git ${TMP_DIR} &&
+  make -C ${TMP_DIR} build_linux &&
+  cp ${TMP_DIR}/target/x86_64-unknown-linux-musl/release/rpm-builder /usr/local/bin/rpm-builder