Add delayed_events table to boolean column port (#19155)

The `delayed_events` table has a boolean column that should be handled by the SQLite->PostgreSQL migration script.

Author: AndrewFerr

changelog.d/19155.bugfix

@@ -0,0 +1 @@
+Let the SQLite-to-PostgreSQL migration script correctly migrate a boolean column in the `delayed_events` table.

synapse/_scripts/synapse_port_db.py

@@ -107,6 +107,7 @@
 BOOLEAN_COLUMNS = {
  "access_tokens": ["used"],
  "account_validity": ["email_sent"],
+ "delayed_events": ["is_processed"],
  "device_lists_changes_in_room": ["converted_to_destinations"],
  "device_lists_outbound_pokes": ["sent"],
  "devices": ["hidden"],