vim-patch:9.2.0323: filetype: buf.lock files are not recognized (#38897)

Problem:  filetype: buf.lock files are not recognized
Solution: Detect buf.lock files as yaml filetype
          (Stefan VanBuren)

Reference:
https://buf.build/docs/configuration/v2/buf-lock/

closes: vim/vim#19935

c2734dc03c

Co-authored-by: Stefan VanBuren <svanburen@buf.build>

runtime/lua/vim/filetype.lua

@@ -2035,6 +2035,7 @@ local filename = {
   ['.clangd'] = 'yaml',
   ['.clang-format'] = 'yaml',
   ['.clang-tidy'] = 'yaml',
+  ['buf.lock'] = 'yaml',
   ['pixi.lock'] = 'yaml',
   ['yarn.lock'] = 'yaml',
   matplotlibrc = 'yaml',