[calls] meson: Don't access the network when validating metadata

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 558393a8cb4172a8f3cf212daddfed1a55dc9723
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Thu Jan 20 08:46:13 2022 +0100

    meson: Don't access the network when validating metadata
    
    Build servers might not allow network access and this shaves off a little time
    in the test suite.
    It shouldn't be a problem running the validation manually when adding new
    screenshots.

 data/meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/data/meson.build b/data/meson.build
index c577180c..46b01816 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -42,6 +42,7 @@ if appstreamcli.found()
   test('Validate metainfo file', appstreamcli,
        args: ['validate',
               '--pedantic',
+              '--no-net',
               join_paths(meson.current_source_dir(),
                          'org.gnome.Calls.metainfo.xml')
              ])