Updated debian changelog for version 6.7.0

debian/changelog

+swh-model (6.7.0-1~swh1) unstable-swh; urgency=medium
+
+  * New upstream release 6.7.0     - (tagged by Nicolas Dandrimont
+    <nicolas@dandrimont.eu> on 2023-04-05 16:08:46 +0200)
+  * Upstream changes:     - Release swh.model v6.7.0     - Add methods
+    to swh.model.model objects to retrieve SWHIDs of depended-on objects
+
+ -- Software Heritage autobuilder (on jenkins-debian1) <jenkins@jenkins-debian1.internal.softwareheritage.org>  Wed, 05 Apr 2023 14:13:11 +0000
+
 swh-model (6.6.3-1~swh1) unstable-swh; urgency=medium
 
   * New upstream release 6.6.3     - (tagged by Antoine Lambert