update DuckDbClient with DuckDb v 0.8

[ericemc3]

Last DuckDb releases (as of 0.8.0) include PIVOT and UNPIVOT, both very useful SQL features for reshaping data.

[Fil]

Documentation:

• https://duckdb.org/docs/sql/statements/pivot
• https://duckdb.org/docs/sql/statements/unpivot

[Fil]

DuckDB 0.8.0 was included in https://github.com/duckdb/duckdb-wasm/releases/tag/v1.26.0

We are currently using 1.24 (89f2700), see https://github.com/observablehq/stdlib/blob/main/src/dependencies.js