[gdk-pixbuf/macos-ci] Minimise bandwidth use for subprojects

[Emmanuele Bassi <ebassi src gnome org>]

commit 7edbb02d453a4d2218088adcfe03a85e07b4f279
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Jan 4 00:46:32 2021 +0000

    Minimise bandwidth use for subprojects
    
    Use `depth=1` to reduce the size of the clone when using subprojects.

 subprojects/glib.wrap | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/subprojects/glib.wrap b/subprojects/glib.wrap
index 87021ae4d..0f72dc280 100644
--- a/subprojects/glib.wrap
+++ b/subprojects/glib.wrap
@@ -3,3 +3,4 @@ directory=glib
 url=https://gitlab.gnome.org/GNOME/glib.git
 push-url=git gitlab gnome org:GNOME/glib.git
 revision=master
+depth=1