vim-patch:9.0.1393: Cairo files are not recognized (#22578)

Problem:    Cairo files are not recognized.
Solution:   Add a pattern for Cairo files. (Amaan Qureshi, closes vim/vim#12118)

ff226d49fe

runtime/lua/vim/filetype.lua

@@ -191,6 +191,7 @@ local extension = {
   BUILD = 'bzl',
   qc = 'c',
   cabal = 'cabal',
+  cairo = 'cairo',
   capnp = 'capnp',
   cdc = 'cdc',
   cdl = 'cdl',