runtime(gp): update gp.vim syntax file for the GP language (version 2.15) (#12884) Commit: https://github.com/vim/vim/commit/c6d533b0ad565a610a48386b0ad72cc591010fcb Author: Karim Belabas <Karim.belabas@math.u-bordeaux.fr> Date: Tue Aug 22 20:25:06 2023 +0200 runtime(gp): update gp.vim syntax file for the GP language (version 2.15) (https://github.com/vim/vim/issues/12884) - add missing defaults - add missing control structures (incl. parallelism) - add missing scope declarations - whitespace edits (remove extra tabs)