Update dependency django-anymail to v12 (#1815)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

poetry.lock

@@ -21,7 +21,7 @@ cryptography = "^43.0.0"
 dj-database-url = "^2.0.0"
 dj-static = "^0.0.6"
 Django = "4.2.16"
-django-anymail = {extras = ["mailgun"], version = "^11.0"}
+django-anymail = {extras = ["mailgun"], version = "^12.0"}
 django-bitfield = "^2.2.0"
 django-cache-memoize = "^0.2.0"
 django-cors-headers = "^4.0.0"