ci: Use ci-templates for building image

This rebuilds the automaticaly whenever the image tag changes. Whenever
something in the image needs to change, alter the installation script
and change the tag to the current date.

This removes the -s (strict) argument from js68, as it doesn't exist in
js78.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1492>

.gitlab-ci/Dockerfile

@@ -1,24 +0,0 @@
-# Rebuild and push with
-#
-#     cd .gitlab-ci/
-#     podman build --format docker --no-cache -t registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v2 .
-#     podman push registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v2
-#
-
-FROM registry.fedoraproject.org/fedora:32
-
-RUN dnf -y update && dnf -y upgrade && \
-    dnf install -y 'dnf-command(copr)' git && \
-
-    # For syntax checks with `find . -name '*.js' -exec js68 -c -s '{}' ';'`
-    dnf install -y findutils mozjs68-devel && \
-
-    # For static analysis with eslint
-    dnf install -y nodejs && \
-    npm install -g eslint && \
-
-    # Shameless plug for my own tooling; useful for generating zip
-    dnf copr enable -y fmuellner/gnome-shell-ci && \
-    dnf install -y gnome-extensions-tool meson && \
-
-    dnf clean all

.gitlab-ci/install-meson-project.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+set -e
+
+if [[ $# -lt 4 ]]; then
+  echo Usage: $0 [options] [repo-url] [commit] [subdir]
+  echo  Options:
+  echo    -Dkey=val
+  exit 1
+fi
+
+MESON_OPTIONS=()
+
+while [[ $1 =~ ^-D ]]; do
+  MESON_OPTIONS+=( "$1" )
+  shift
+done
+
+REPO_URL="$1"
+COMMIT="$2"
+SUBDIR="$3"
+PREPARE="$4"
+
+REPO_DIR="$(basename ${REPO_URL%.git})"
+
+git clone --depth 1 "$REPO_URL" -b "$COMMIT"
+pushd "$REPO_DIR"
+pushd "$SUBDIR"
+sh -c "$PREPARE"
+meson --prefix=/usr _build "${MESON_OPTIONS[@]}"
+ninja -C _build install
+popd
+popd
+rm -rf "$REPO_DIR"