CI: add a -deps shell script for EndeavourOS

ci/deps-endeavouros.sh

+#! /bin/sh
+#
+# Install dependencies for building on EndeavourOS
+#
+# There is no docker image for EndeavoudOS, and the live ISO
+# for Cassini Nova is KF5 / Qt5 based, but we can build there.
+# It even has most of the build-deps already installed.
+pacman -Syu --noconfirm git cmake ninja jq
+pacman -S --noconfirm gcc yaml-cpp icu
+pacman -S --noconfigm extra-cmake-modules
+