fix(duckdb): do not cascade table/view drops in DuckLake catalogs

[kingjaiteh]

Fixes #6032

DuckLake does not implement DROP TABLE ... CASCADE or DROP VIEW ... CASCADE and raises "Cascade Drop not supported in DuckLake". Since #5133 the janitor always deletes snapshot tables with cascade=True, so on a DuckLake catalog it can never reclaim space and silently reports "Cleanup complete." until a snapshot expires.

Cascade support is declared per engine adapter (SUPPORTED_DROP_CASCADE_OBJECT_KINDS), but on DuckDB it varies per attached catalog: a native catalog accepts DROP TABLE ... CASCADE, a DuckLake catalog attached in the same connection does not.

Changes:

• DuckDBEngineAdapter._drop_object resolves the target catalog (explicit catalog on the name, else the current one) and looks up its type in duckdb_databases(). For ducklake it drops TABLE/VIEW without CASCADE. SCHEMA drops are untouched, DuckLake supports cascade there.
• The lookup is factored into _get_catalog_type, which _create_table already did inline for the DuckLake partitioning check, so both share it.
• Native DuckDB catalogs behave exactly as before, so users running with enable_view_dependencies keep cascade.

The list-only alternative (removing TABLE/VIEW from the DuckDB cascade list) would also fix DuckLake but would regress enable_view_dependencies on native catalogs, which is what #4767 added it for.

Test Plan

• test_drop_table_ducklake_no_cascade attaches a real DuckLake catalog (same setup as test_ducklake_partitioning), creates a table with a dependent view in it and a native table/view in memory, and drops all four with cascade=True. Fails on main with the NotImplementedException above.
• test_drop_object_cascade_by_catalog_type asserts the emitted SQL with a mocked adapter: no CASCADE for DuckLake table/view, CASCADE kept for DuckLake schema and for a native catalog table.
• tests/core/engine_adapter/test_duckdb.py and tests/core/test_snapshot_evaluator.py pass on DuckDB 1.5.5, Python 3.12, Windows.
• The issue reporter has offered to run the branch against their DuckLake project.

Checklist

• I have run make style and fixed any issues
• I have added tests for my changes (if applicable)
• All existing tests pass (make fast-test)
• My commits are signed off (git commit -s) per the DCO

[StuffbyYuki]

@kingjaiteh Thanks for the PR! No blocker but a few things:

• Case-insensitive catalog match: _drop_object takes the catalog from the table name, which SQLMesh lowercases. Aliases in catalogs: are attached with their case kept, though (e.g. MyLake), so database_name = 'mylake' misses and CASCADE comes back. Comparing LOWER(database_name) = LOWER(catalog) in _get_catalog_type would fix it.
• Please add "Fixes # 6032" to the description so the issue closes on merge.

[kingjaiteh]

Thanks @StuffbyYuki! Both done: _get_catalog_type now compares LOWER(database_name) = LOWER(catalog), with a test that attaches a DuckLake catalog as "MyLake" and drops through the lowercased name. Also added Fixes #6032 to the description.