We do not need the service file for systemd.

--- glib-networking-2.80.1/proxy/libproxy/meson.build.orig
+++ glib-networking-2.80.1/proxy/libproxy/meson.build
@@ -11,16 +11,6 @@
   configuration: service_conf
 )
 
-service = 'glib-pacrunner.service'
-
-configure_file(
-  input: service + '.in',
-  output: service,
-  install: true,
-  install_dir: join_paths('lib', 'systemd', 'user'),
-  configuration: service_conf
-)
-
 sources = files(
   'glibproxyresolver.c',
   'libproxy-module.c'