vim-patch:9.1.0435: filetype: cygport files are not recognized

Problem:  filetype: cygport files are not recognized
Solution: Recognize '*.cygport' files as sh filetype
          (Ken Takata)

https://cygwin.github.io/cygport/cygport_in.html

closes: vim/vim#14833

cd79f8fbd3

Co-authored-by: K.Takata <kentkt@csc.jp>

runtime/lua/vim/filetype.lua

@@ -948,6 +948,7 @@ local extension = {
   sexp = 'sexplib',
   bash = detect.bash,
   bats = detect.bash,
+  cygport = detect.bash,
   ebuild = detect.bash,
   eclass = detect.bash,
   env = detect.sh,