hsqldb: 1.8.0.9 -> 2.4.0

Semi-automatic update. These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 2.4.0 with grep in /nix/store/4179pxpwkjn7xk7rj0g538zjhsx9xzy1-hsqldb-2.4.0