Removes a column in place with ALTER TABLE ... DROP COLUMN. This is a
metadata-only change: the column disappears from the current schema, but
earlier snapshots still contain it and remain queryable through time
travel.
See also
add_table_column(), rename_table_column(),
get_ducklake_table_version() to read snapshots that still have the
column
Other schema evolution:
add_table_column(),
rename_ducklake_table(),
rename_table_column(),
set_column_type()
