Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools. This update was made based on information from https://repology.org/metapackage/swig/versions
SWIG 4 is not a complete replacement for SWIG 3 because it has removed support for CFFI, Allegrocl, Chicken, CLISP, S-EXP, UFFI, Pike, Modula3.