vim-patch:9.1.1709: filetype: kyaml files are not recognized

Problem:  filetype: kyaml files are not recognized
Solution: Detect *.kyml files as yaml filetype
          (Volodymyr Chernetskyi)

References:
- https://kubernetes.io/blog/2025/08/27/kubernetes-v1-34-release/#alpha-support-for-kyaml-a-kubernetes-dialect-of-yaml

closes: vim/vim#18158

vim/vim@d5c89cc

Co-authored-by: Volodymyr Chernetskyi <19735328+chernetskyi@users.noreply.github.com>

Author: chernetskyi

runtime/lua/vim/filetype.lua

@@ -1392,6 +1392,8 @@ local extension = {
   yaml = 'yaml',
   eyaml = 'yaml',
   mplstyle = 'yaml',
+  kyaml = 'yaml',
+  kyml = 'yaml',
   grc = detect_line1('<%?xml', 'xml', 'yaml'),
   yang = 'yang',
   yuck = 'yuck',

test/old/testdir/test_filetype.vim

@@ -927,7 +927,7 @@ func s:GetFilenameChecks() abort
     \ 'xsd': ['file.xsd'],
     \ 'xslt': ['file.xsl', 'file.xslt'],
     \ 'yacc': ['file.yy', 'file.yxx', 'file.y++'],
-    \ 'yaml': ['file.yaml', 'file.yml', 'file.eyaml', 'any/.bundle/config', '.clangd', '.clang-format', '.clang-tidy', 'file.mplstyle', 'matplotlibrc', 'yarn.lock',
+    \ 'yaml': ['file.yaml', 'file.yml', 'file.eyaml', 'file.kyaml', 'file.kyml', 'any/.bundle/config', '.clangd', '.clang-format', '.clang-tidy', 'file.mplstyle', 'matplotlibrc', 'yarn.lock',
     \          '/home/user/.kube/config', '.condarc', 'condarc', 'pixi.lock'],
     \ 'yang': ['file.yang'],
     \ 'yuck': ['file.yuck'],