vim-patch:9.1.1764: filetype: CODEOWNERS file not recognized (#35789)

Problem:  filetype: CODEOWNERS file not recognized
Solution: Detect CODEOWNERS file as codeowners filetype, include a
          syntax and filetype plugin (Jon Parise).

CODEOWNERS files define code ownership rules for GitHub-hosted (and
other) repositories. The syntax is similar to 'gitignore' files but
differs in enough ways to warrant its own filetype.

References:
- https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners

closes: vim/vim#18299

817e4d3ee6

Co-authored-by: Jon Parise <jon@indelible.org>

runtime/lua/vim/filetype.lua

@@ -1516,6 +1516,7 @@ local filename = {
   ['.trans'] = 'clojure',
   ['CMakeLists.txt'] = 'cmake',
   ['CMakeCache.txt'] = 'cmakecache',
+  ['CODEOWNERS'] = 'codeowners',
   ['.cling_history'] = 'cpp',
   ['.alias'] = detect.csh,
   ['.cshrc'] = detect.csh,