[ci] Add a Void Linux bot

https://voidlinux.org/ is yet another and different distro written from scratch, thus completely eligible to have a bot here!

Seriously however not that useful yet however but I will try to overload it other tasks later, like our other bots.

No test yet also, couldn't install cairo-devel, will try to fix that later.

Their harfbuzz package source: https://github.com/void-linux/void-packages/blob/master/srcpkgs/harfbuzz/template

.circleci/config.yml

@@ -63,7 +63,7 @@ jobs:
       - image: base/devel
     steps:
       - checkout
-      - run: pacman --noconfirm -Syu freetype2 cairo icu gettext gobject-introspection gcc gcc-libs glib2 graphite pkg-config ragel python python-pip
+      - run: pacman --noconfirm -Syu freetype2 cairo icu gettext gobject-introspection gcc gcc-libs glib2 graphite pkg-config ragel python python-pip make
       - run: pip install flake8 fonttools
       - run: flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
       # C??FLAGS are not needed for a regular build
@@ -71,6 +71,14 @@ jobs:
       - run: make -j32 CPPFLAGS="-Werror"
       - run: make check CPPFLAGS="-Werror" || .ci/fail.sh
       
+  void-notest:
+    docker:
+      - image: voidlinux/voidlinux
+    steps:
+      - checkout
+      - run: xbps-install -Suy freetype gettext gcc glib graphite pkg-config ragel libtool autoconf automake make
+      - run: ./autogen.sh && make -j32 && make check
+
   clang-O3-O0:
     docker:
       - image: multiarch/crossbuild
@@ -307,6 +315,7 @@ workflows:
       # autotools based builds
       - alpine-O3-NOMMAP
       - archlinux-py3-all
+      - void-notest
       - gcc-valgrind
       - clang-O3-O0
       - clang-everything