fix(safe-history-indexes): Guard 0039 indexes against missing historical columns (LANG-135)

src/langbot/pkg/persistence/alembic/versions/0039_execution_lease_indexes.py

@@ -33,6 +33,8 @@ def upgrade():
     for table, index, columns in INDEXES:
         if not inspector.has_table(table):
             continue
+        if not set(columns) <= {column['name'] for column in inspector.get_columns(table)}:
+            continue
         # Fresh installations create these indexes from ORM metadata before migrations.
         if index not in {item['name'] for item in inspector.get_indexes(table)}:
             op.create_index(index, table, columns)