I've been beating my head trying to get duckdb to statically link into a Go program (I'm neither an expert with cgo nor ld). If anyone else has been able to do this I'd love to see your build steps. https://github.com/marcboeker/go-duckdb produces a non-static binary by default.
Did you try Zig? https://dev.to/kristoff/zig-makes-go-cross-compilation-just-...
DuckDB needs Python3 to build as well, so not sure how easy it might be to get it cross-compile with Zig CC.