vim-patch:9.0.1014: zir files are not recognized (#21301)

Problem:    Zir files are not recognized.
Solution:   Add a pattern for Zir files. (closes vim/vim#11664)

25201016d5

Co-authored-by: Bram Moolenaar <Bram@vim.org>

runtime/lua/vim/filetype.lua

@@ -1122,6 +1122,7 @@ local extension = {
   yang = 'yang',
   ['z8a'] = 'z8a',
   zig = 'zig',
+  zir = 'zir',
   zu = 'zimbu',
   zut = 'zimbutempl',
   zsh = 'zsh',