vim-patch:9.1.0317: filetype: matplotlibrc files are not recognized

Problem:  filetype: matplotlibrc files are not recognized
Solution: Detect 'matplotlibrc' file as yaml filetype
          (Wu, Zhenyu)

See: https://matplotlib.org/stable/users/explain/customizing.html#the-matplotlibrc-file

closes: vim/vim#14501

55d4f3c006

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

runtime/lua/vim/filetype.lua

@@ -1660,6 +1660,7 @@ local filename = {
   ['.clang-format'] = 'yaml',
   ['.clang-tidy'] = 'yaml',
   ['yarn.lock'] = 'yaml',
+  matplotlibrc = 'yaml',
   zathurarc = 'zathurarc',
   ['/etc/zprofile'] = 'zsh',
   ['.zlogin'] = 'zsh',