[rhythmbox/wip/sam/meson] ci: Install Meson from PyPI

[Sam Thursfield <sthursfield src gnome org>]

commit f350a0b824f1199362326446a9ca3946ecfe61ef
Author: Sam Thursfield <sam afuera me uk>
Date:   Thu Oct 29 12:04:20 2020 +0100

    ci: Install Meson from PyPI
    
    Ubuntu 18.04 has a very old version available.

 .gitlab-ci.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 754bd9a48..bcbc4963f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,9 +12,10 @@ before_script:
                        libsoup2.4-dev libgudev-1.0-dev libmtp-dev libnotify-dev
                        libbrasero-media3-dev
                        libsecret-1-dev libpeas-dev yelp-tools x11proto-core-dev
-                       liblircclient-dev python3-dev python-gi-dev
+                       liblircclient-dev python3-dev python-gi-dev python3-pip
                        libdmapsharing-3.0-dev libjson-glib-dev libgrilo-0.3-dev
-                       libxml2-dev libtdb-dev meson ninja-build
+                       libxml2-dev libtdb-dev ninja-build
+  - pip3 install meson
 
 test:
   stage: test