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/build-snd-dummy.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+set -eu
+
+LINUX_VERSION=$(uname -r | cut -d. -f1-2)
+LINUX_ARCHIVE_FILE=v${LINUX_VERSION}.tar.gz
+LINUX_SOURCE_DIR=linux-${LINUX_VERSION}
+
+mkdir -p "${TMPDIR}"
+cd "${TMPDIR}"
+
+wget -q "https://github.com/torvalds/linux/archive/${LINUX_ARCHIVE_FILE}"
+
+tar -xf "${LINUX_ARCHIVE_FILE}" "${LINUX_SOURCE_DIR}/sound"
+cd "${LINUX_SOURCE_DIR}/sound"
+
+CC=gcc make -C "/lib/modules/$(uname -r)/build" M="${PWD}" CONFIG_SOUND=m CONFIG_SND=m CONFIG_SND_PCM=m CONFIG_SND_DUMMY=m modules
+
+mkdir -p "${SND_DUMMY_DIR}"
+cp soundcore.ko core/snd.ko core/snd-pcm.ko drivers/snd-dummy.ko "${SND_DUMMY_DIR}"

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