.github: ubuntu: fix apt cache

The previous approach flooded the repository with new caches,
thus leading to unnecessary eviction of other caches. Previously
had splitted restore and save, but that required using separate
keys, and github doesn't report partial cache hits (prefix-only),
thus no chance of skipping unnecessary cache saves.

Instead now moving out populating the cache into a separate job,
which is run before all those who need the cache. This also allows
us skipping `apt-get update` in the individual jobs, thus saving
a bit more time.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

.github/scripts/ubuntu/fetch-pkg.sh

@@ -0,0 +1,103 @@
+#!/bin/bash
+
+# NOTE: don't forget to update both fetch-pkg and install-pkg and change cache name
+
+set -e
+
+# Packages which are needed by this script, but not for the xserver build
+EPHEMERAL="
+	libexpat-dev
+	libgles2-mesa-dev
+	libxkbcommon-dev
+	x11-utils
+	x11-xserver-utils
+	xauth
+	xvfb
+"
+
+apt-get update
+
+apt-get install -d -y \
+	$EPHEMERAL \
+	autoconf \
+	automake \
+	build-essential \
+	ca-certificates \
+	libaudit-dev \
+	libbsd-dev \
+	libcairo2-dev \
+	libdbus-1-dev \
+	libdrm-dev \
+	libegl1-mesa-dev \
+	libepoxy-dev \
+	libevdev2 \
+	libexpat1 \
+	libffi-dev \
+	libgbm-dev \
+	libgcrypt-dev \
+	libgl1-mesa-dev \
+	libgles2 \
+	libglx-mesa0 \
+	libinput10 \
+	libinput-dev \
+	libnvidia-egl-wayland-dev \
+	libpciaccess-dev \
+	libpixman-1-dev \
+	libspice-protocol-dev \
+	libsystemd-dev \
+	libtool \
+	libudev-dev \
+	libunwind-dev \
+	libx11-dev \
+	libx11-xcb-dev \
+	libxau-dev \
+	libxaw7-dev \
+	libxcb-glx0-dev \
+	libxcb-icccm4-dev \
+	libxcb-image0-dev \
+	libxcb-keysyms1-dev \
+	libxcb-randr0-dev \
+	libxcb-render-util0-dev \
+	libxcb-render0-dev \
+	libxcb-shape0-dev \
+	libxcb-shm0-dev \
+	libxcb-util0-dev \
+	libxcb-xf86dri0-dev \
+	libxcb-xkb-dev \
+	libxcb-xv0-dev \
+	libxcb1-dev \
+	libxdmcp-dev \
+	libxext-dev \
+	libxfixes-dev \
+	libxfont-dev \
+	libxi-dev \
+	libxinerama-dev \
+	libxkbcommon0 \
+	libxkbfile-dev \
+	libxmu-dev \
+	libxmuu-dev \
+	libxpm-dev \
+	libxrandr-dev \
+	libxrender-dev \
+	libxres-dev \
+	libxshmfence-dev \
+	libxt-dev \
+	libxtst-dev \
+	libxv-dev \
+	mesa-common-dev \
+	meson \
+	nettle-dev \
+	libpango1.0-dev \
+	pkg-config \
+	x11-xkb-utils \
+	xfonts-utils \
+	xkb-data \
+	xutils-dev \
+	libxaw7-dev \
+	python3-mako \
+	libxcvt-dev \
+	git \
+	sudo
+
+# only pull them into apt cache -- for mingw32 build
+apt-get install -d -y mingw-w64-tools gcc-mingw-w64 gcc-mingw-w64-i686 libz-mingw-w64-dev

.github/scripts/ubuntu/install-pkg.sh

@@ -13,8 +13,6 @@ EPHEMERAL="
 	xvfb
 "
 
-apt-get update
-
 apt-get install -y \
 	$EPHEMERAL \
 	autoconf \
@@ -96,6 +94,3 @@ apt-get install -y \
 	libxcvt-dev \
 	git \
 	sudo
-
-# only pull them into apt cache -- for mingw32 build
-apt-get install -d -y mingw-w64-tools gcc-mingw-w64 gcc-mingw-w64-i686 libz-mingw-w64-dev