vim-patch:9.0.0711: SubStation Alpha files are not recognized (#20577)

Problem:    SubStation Alpha files are not recognized.
Solution:   Add patterns for SubStation Alpha files. (closes vim/vim#11332)
084f2620ec

runtime/filetype.vim

@@ -1751,6 +1751,9 @@ au BufNewFile,BufRead *.sed			setf sed
 " SubRip
 au BufNewFile,BufRead *.srt			setf srt
 
+" SubStation Alpha
+au BufNewFile,BufRead *.ass,*.ssa		setf ssa
+
 " svelte
 au BufNewFile,BufRead *.svelte			setf svelte
 

runtime/lua/vim/filetype.lua

@@ -970,6 +970,8 @@ local extension = {
   mot = 'srec',
   ['s19'] = 'srec',
   srt = 'srt',
+  ssa = 'ssa',
+  ass = 'ssa',
   st = 'st',
   imata = 'stata',
   ['do'] = 'stata',