chore(migrations): migrate related name on some many:many fields

This is basically a no-op, just Django cleaing up some old stuff.
Previously, the `related_name` was set to some value that's invalid/unused now,
but hasn't been detected in a long time.

caluma/caluma_form/migrations/0047_alter_answer_documents.py

@@ -0,0 +1,21 @@
+# Generated by Django 4.2.9 on 2024-01-23 14:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("caluma_form", "0046_file_answer_reverse_keys"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="answer",
+            name="documents",
+            field=models.ManyToManyField(
+                related_name="+",
+                through="caluma_form.AnswerDocument",
+                to="caluma_form.document",
+            ),
+        ),
+    ]

caluma/caluma_workflow/migrations/0032_alter_workflow_start_tasks.py

@@ -0,0 +1,21 @@
+# Generated by Django 4.2.9 on 2024-01-23 14:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("caluma_workflow", "0031_simple_history"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="workflow",
+            name="start_tasks",
+            field=models.ManyToManyField(
+                help_text="Starting task(s) of the workflow.",
+                related_name="+",
+                to="caluma_workflow.task",
+            ),
+        ),
+    ]