vim-patch:9.0.1281: Cadence files are not recognized (#22130)

Problem:    Cadence files are not recognized.
Solution:   Recognize Cadence files. (Janez Podhostnik, closes vim/vim#11951)

cb626a4692

Co-authored-by: Janez Podhostnik <janez.podhostnik@gmail.com>

src/nvim/testdir/test_filetype.vim

@@ -522,6 +522,7 @@ let s:filename_checks = {
     \ 'sinda': ['file.sin', 'file.s85'],
     \ 'sisu': ['file.sst', 'file.ssm', 'file.ssi', 'file.-sst', 'file._sst', 'file.sst.meta', 'file.-sst.meta', 'file._sst.meta'],
     \ 'skill': ['file.il', 'file.ils', 'file.cdf'],
+    \ 'cdc': ['file.cdc'],
     \ 'slang': ['file.sl'],
     \ 'slice': ['file.ice'],
     \ 'slpconf': ['/etc/slp.conf', 'any/etc/slp.conf'],