0.81.0

What's Changed

• Add file-level user metadata by @mprammer in #8740
• refactor[array]: serialization context filter by ids (not whole registry) by @joseph-isaacs in #8897
• StructReader::partition_expr doesn't hold lock if the expression is being newly partitioned by @robert3005 in #8892
• Add UnionArray by @connortsui20 in #8834
• Don't emit STB_UNIQUE symbols in GCC for vortex-duckdb by @myrrc in #8913

Full Changelog: 0.80.0...0.81.0