Support Iceberg DROP SCHEMA CASCADE fallback #1698

Job	Run time
unit-tests	1m 10s
Verify cmd/duckgres-controlplane does not link libduckdb	1m 10s
lint	1m 13s
controlplane-k8s-tests	1m 53s
k8s-integration-tests	7m 16s
integration-tests	4m 33s
controlplane-tests	1m 38s
configstore-integration-tests	1m 36s
	20m 29s

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