Use github tags instead of releases for d/watch.

debian/changelog

+python-django-timezone-field (4.2.1-2) UNRELEASED; urgency=medium
+
+  * Use github tags instead of releases for d/watch.
+
+ -- Michael Fladischer <fladi@debian.org>  Tue, 18 Jan 2022 07:52:27 +0000
+
 python-django-timezone-field (4.2.1-1) unstable; urgency=low
 
   [ Diego M. Rodriguez ]

debian/watch

 version=4
 opts=filenamemangle=s/.*\/([\d\.]+.*)$/python-django-timezone-field-$1/ \
-https://github.com/mfogel/django-timezone-field/releases \
+https://github.com/mfogel/django-timezone-field/tags \
 /mfogel/django-timezone-field/archive/refs/tags/([\d\.]+)\.tar\.gz