how to build as of 2025-09-04

[ocadaruma]

jfrv and dudkdb-jfr-extension depend on outdated rustc and rust dependencies, which is not straightforward to build. this is a memo to how to make it work (without code change 😛)

• Apple clang version 16.0.0
• Use cmake 3.x
• Use emsdk 3.1.42
• Use rust toolchain 2023-10-05
• Use this Cargo.lock for duckdb-jfr-extension
• Use node v18

Then follow the instruction in README.md