[gnome-build-meta/valentindavid/buildstream-1.6] Update buildstream to 1.6.1 and bst-external to 0.21

[Valentin David <valentindavid src gnome org>]

commit 27ea78385cce47fadb33a628695b29581036a685
Author: Valentin David <valentin david codethink co uk>
Date:   Wed Nov 18 13:27:28 2020 +0100

    Update buildstream to 1.6.1 and bst-external to 0.21

 elements/vm/buildstream/bst-external.bst | 2 +-
 elements/vm/buildstream/buildstream.bst  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/elements/vm/buildstream/bst-external.bst b/elements/vm/buildstream/bst-external.bst
index 13fed84db..2194b2c9e 100644
--- a/elements/vm/buildstream/bst-external.bst
+++ b/elements/vm/buildstream/bst-external.bst
@@ -3,7 +3,7 @@ kind: distutils
 sources:
 - kind: git_tag
   url: https://gitlab.com/BuildStream/bst-external.git
-  track: 0.20.0
+  track: 0.21.0
 
 build-depends:
 - freedesktop-sdk.bst:components/python3-setuptools-scm.bst
diff --git a/elements/vm/buildstream/buildstream.bst b/elements/vm/buildstream/buildstream.bst
index 1f8683304..22f57c3d1 100644
--- a/elements/vm/buildstream/buildstream.bst
+++ b/elements/vm/buildstream/buildstream.bst
@@ -2,7 +2,7 @@ kind: distutils
 
 sources:
 - kind: tar
-  url: https://download.gnome.org/sources/BuildStream/1.4/BuildStream-1.4.3.tar.xz
+  url: https://download.gnome.org/sources/BuildStream/1.6/BuildStream-1.6.1.tar.xz
 
 depends:
 - sdk-deps/bubblewrap.bst