[gtk/gst-subproject] Add a gst-build subproject

[Matthias Clasen <matthiasc src gnome org>]

commit 251e296b7fac29d6660c73b97de2a24d29360f5e
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Mar 25 21:26:19 2021 -0400

    Add a gst-build subproject
    
    This should help to reach 100% 'build from git'
    status.
    
    Fixes: #3795

 subprojects/gst-build.wrap | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/subprojects/gst-build.wrap b/subprojects/gst-build.wrap
new file mode 100644
index 0000000000..c160ac2fe4
--- /dev/null
+++ b/subprojects/gst-build.wrap
@@ -0,0 +1,6 @@
+[wrap-git]
+url=https://gitlab.freedesktop.org/gstreamer/gst-build.git
+revision=master
+
+[provide]
+dependency_names=gstreamer-player-1.0