dev-util/update-copyright: Update to git-r3 and bump Python

Generated with:

  $ git submodule update --remote dev-util/update-copyright

diff --git a/dev-util/update-copyright b/dev-util/update-copyright
index 2c9b3bc2c8b9a2003f1950861817ba7bd88fc6d0..706fed27f8411013763570117eee70b29373adcc 160000 (submodule)
--- a/dev-util/update-copyright
+++ b/dev-util/update-copyright
@@ -1 +1 @@
-Subproject commit 2c9b3bc2c8b9a2003f1950861817ba7bd88fc6d0
+Subproject commit 706fed27f8411013763570117eee70b29373adcc