refactor(nix): clean up marker argument construction
Make the argument construction robust to an empty backend list
feat(snowflake): implement ops.BitwiseAnd, ops.BitwiseNot, ops.Bitwis…
…eOr, ops.BitwiseXor
fix(duckdb): workaround an ownership bug at the interaction of duckdb…
…, pandas and pyarrow
refactor(datatype): use a dictionary to store StructType fields rat…
…her than `names` and `types` tuples BREAKING CHANGE: `Struct(names, types)` is not supported anymore, pass a dictionary to `Struct` constructor instead