Improve logging in the subscription validation task

Fix an issue where validation workflows would run out-of-order, or in duplicate.

gso/cli/schedule.py

+"""CLI for interacting with the task scheduler. Only supports running a single task."""
+
+# <!-- vale off -->
+# Copyright 2019-2020 SURF.
+# Copyright 2025 GÉANT Vereniging.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# <!-- vale on -->
+
+import logging
+from collections.abc import Callable
+
+import typer
+
+from gso.schedules.clean_old_tasks import clean_old_tasks
+from gso.schedules.send_email_notifications import send_email_notifications
+from gso.schedules.validate_products import validate_products
+from gso.schedules.validate_subscriptions import validate_subscriptions
+
+logger = logging.getLogger(__name__)
+
+app: typer.Typer = typer.Typer()
+
+ALL_SCHEDULES: list[Callable] = [
+    clean_old_tasks,
+    send_email_notifications,
+    validate_products,
+    validate_subscriptions,
+]
+
+
+@app.command()
+def run_task(task_name: str) -> None:
+    """Force the execution of a task by name."""
+    for s in ALL_SCHEDULES:
+        if task_name == s.__name__:
+            s()