Update Dependabot to use wildcards (#1556)

Author: Dreamsorcerer

requirements-dev.txt

@@ -1,14 +1,3 @@
-# Workaround for https://github.com/dependabot/dependabot-core/issues/2178
--r demos/blog/requirements.txt
--r demos/chat/requirements.txt
--r demos/graphql-demo/requirements-dev.txt
--r demos/imagetagger/requirements.txt
--r demos/moderator/requirements-dev.txt
--r demos/moderator_bot/requirements-dev.txt
--r demos/motortwit/requirements.txt
--r demos/polls/requirements-dev.txt
--r demos/shortify/requirements.txt
-
 # lint
 flake8==7.3.0
 flake8-bugbear==24.12.12