duckdb 1.4.4

Features

• Update to DuckDB v1.4.4, see https://github.com/duckdb/duckdb/releases/tag/v1.4.4 for details.

• Add operator expressions (@toppyy, #1828).

Chore

• Bump vendored cpp11 to v0.5.3.

Documentation

• Add alternative installation method to README (@szarnyasg, #1819).