Remove ref to use default branch for include

This merge request remove the ref keyword in the template inclusion block so that by default when a pipeline runs, it will use the default branch of the source project.

conda/meta.yaml

-# Copyright © 2022 Idiap Research Institute <contact@idiap.ch>
+# SPDX-FileCopyrightText: Copyright © 2022 Idiap Research Institute <contact@idiap.ch>
 #
 # SPDX-License-Identifier: BSD-3-Clause