vim-patch:9.1.0295: filetype: pip config files are not recognized

Problem:  filetype: pip config files are not recognized
Solution: detect pip.conf as dosini filetype
          (Wu, Zhenyu)

closes: vim/vim#14448

d2b95b8446

Co-authored-by: Wu, Zhenyu <wuzhenyu@ustc.edu>

runtime/lua/vim/filetype.lua

@@ -1327,6 +1327,7 @@ local filename = {
   npmrc = 'dosini',
   ['/etc/yum.conf'] = 'dosini',
   ['.npmrc'] = 'dosini',
+  ['pip.conf'] = 'dosini',
   ['setup.cfg'] = 'dosini',
   ['pudb.cfg'] = 'dosini',
   ['.coveragerc'] = 'dosini',