patch 8.2.2150: Github actions CI isn't used for all available platforms

Problem:    Github actions CI isn't used for all available platforms.
Solution:   Update the github workflows. (Ozaki Kiichi, closes #7433)

ci/setup-xvfb.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+set -e
+
+apt-get install -y xvfb
+
+cat <<EOT >/etc/systemd/system/xvfb.service
+[Unit]
+Description=X Virtual Frame Buffer Service
+After=network.target
+[Service]
+ExecStart=/usr/bin/Xvfb :99 -screen 0 1024x768x24
+[Install]
+WantedBy=multi-user.target
+EOT
+
+systemctl enable xvfb.service
+systemctl start xvfb.service