vim-patch:9.0.2148: Vim does not detect pacman.log file

Problem:  Vim does not detect pacman.log file
Solution: Detect pacmanlogs and add syntax highlighting

pacman.log is a filetype common to Arch Liux and related distributions.
Add some simple syntax highlighting for the pacmanlog filetype.

closes: vim/vim#13618

1e5d66408e

Co-authored-by: Ronan Pigott <ronan@rjp.ie>

runtime/lua/vim/filetype.lua

@@ -1394,6 +1394,7 @@ local filename = {
   octaverc = 'octave',
   ['octave.conf'] = 'octave',
   opam = 'opam',
+  ['pacman.log'] = 'pacmanlog',
   ['/etc/pam.conf'] = 'pamconf',
   ['pam_env.conf'] = 'pamenv',
   ['.pam_environment'] = 'pamenv',