Remove unnecessary recurring execution cleanup task

This task is unnecessary because the
`solid_queue_recurring_executions` table has a foreign key to
`solid_queue_jobs` with `on_delete: :cascade`.

This config was cargo-culted from HEY (in 44429644), which *does* need
this task to run because we've omitted the FK constraints there.

db/queue_schema.rb

@@ -132,6 +132,7 @@ ActiveRecord::Schema[8.2].define(version: 1) do
     t.index ["key"], name: "index_solid_queue_semaphores_on_key", unique: true
   end
 
+  # If these FKs are removed, make sure to periodically run `RecurringExecution.clear_in_batches`
   add_foreign_key "solid_queue_blocked_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
   add_foreign_key "solid_queue_claimed_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
   add_foreign_key "solid_queue_failed_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade