* gnu/packages/games.scm (gzdoom): Update to 4.3.2.
[source]: Use GIT-FETCH and GIT-FILE-NAME. Apply system libgme patch.
Update snippet.
[arguments]: Allow system libgme. Update substitution file names.
[inputs]: Use fluidsynth@2.
* gnu/packages/patches/gzdoom-find-system-libgme.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.