fix(clickhouse): combine task event storage alters

Author: carderne

internal-packages/clickhouse/schema/042_reduce_task_events_v2_storage_overhead.sql

@@ -2,16 +2,12 @@
 
 -- Full-text search is served outside the source event table. Keeping these
 -- indexes here adds work to every event insert and merge without serving reads.
-ALTER TABLE trigger_dev.task_events_v2
-    DROP INDEX IF EXISTS idx_attributes_text_search;
-
-ALTER TABLE trigger_dev.task_events_v2
-    DROP INDEX IF EXISTS idx_message_text_search;
-
 -- attributes remains an insert input for attributes_text, but is no longer
 -- stored. Writers must include attributes in an explicit insert column list
 -- because implicit INSERT column lists exclude EPHEMERAL columns.
 ALTER TABLE trigger_dev.task_events_v2
+    DROP INDEX IF EXISTS idx_attributes_text_search,
+    DROP INDEX IF EXISTS idx_message_text_search,
     MODIFY COLUMN attributes JSON EPHEMERAL;
 
 -- +goose Down