migrations: catch up model change

The station branch was older than when I made added_at mandatory, but
was merged later.

APITaxi_models2/migrations/versions/20230208_13:32:21_861188cd0769_station_added_at_update.py

@@ -0,0 +1,28 @@
+"""station.added_at update
+
+Revision ID: 861188cd0769
+Revises: ed669e53e432
+Create Date: 2023-02-08 13:32:21.599609
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '861188cd0769'
+down_revision = 'ed669e53e432'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.alter_column('station', 'added_at',
+               existing_type=postgresql.TIMESTAMP(),
+               nullable=False)
+
+
+def downgrade():
+    op.alter_column('station', 'added_at',
+               existing_type=postgresql.TIMESTAMP(),
+               nullable=True)