Part of adopting a uniform naming policy for bridge variables,
where the variable prefix matches the role directory name.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Possibly fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3900

This patch hasn't been tested.