Add ability to build GTK app AppImage (#240)

#238 Add AppImage build support

Implements

- Downgrade to libadwaita 1.3 for wider distro support
- Add build script, workflow, and docs for AppImage
- Add build docs for Debian (apt) and Void Linux
- Building AppImage in CI

burrow-gtk/build-aux/build_appimage.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+set -ex
+
+BURROW_GTK_ROOT="$(readlink -f $(dirname -- "$(readlink -f -- "$BASH_SOURCE")")/..)"
+BURROW_GTK_BUILD="$BURROW_GTK_ROOT/build-appimage"
+LINUXDEPLOY_VERSION="${LINUXDEPLOY_VERSION:-"1-alpha-20240109-1"}"
+
+if [ "$BURROW_GTK_ROOT" != $(pwd) ]; then
+    echo "Make sure to cd into burrow-gtk"
+    exit 1
+fi
+
+ARCHITECTURE=$(lscpu | grep Architecture | awk '{print $2}')
+
+if [ "$ARCHITECTURE" == "x86_64" ]; then
+    wget "https://github.com/linuxdeploy/linuxdeploy/releases/download/$LINUXDEPLOY_VERSION/linuxdeploy-x86_64.AppImage" -o /dev/null -O /tmp/linuxdeploy
+    chmod a+x /tmp/linuxdeploy
+elif [ "$ARCHITECTURE" == "aarch64" ]; then
+    wget "https://github.com/linuxdeploy/linuxdeploy/releases/download/$LINUXDEPLOY_VERSION/linuxdeploy-aarch64.AppImage" -o /dev/null -O /tmp/linuxdeploy
+    chmod a+x /tmp/linuxdeploy
+fi
+
+meson setup $BURROW_GTK_BUILD --bindir bin --prefix /usr
+meson compile -C $BURROW_GTK_BUILD
+DESTDIR=AppDir meson install -C $BURROW_GTK_BUILD
+/tmp/linuxdeploy --appimage-extract-and-run --appdir $BURROW_GTK_BUILD/AppDir --output appimage
+mv *.AppImage $BURROW_GTK_BUILD