patch 9.2.0217: filetype: cto files are not recognized

Problem:  filetype: cto files are not recognized
Solution: Detect *.cto as concerto filetype (Jamie Shorten)

Add filetype detection for the Concerto Modelling Language. Concerto
is a schema language by the Accord Project for defining data models
used in smart legal contracts and business networks.

Reference:
Language spec: https://concerto.accordproject.org
Tree-sitter grammar: https://github.com/accordproject/concerto-tree-sitter

closes: #19760

Signed-off-by: Jamie Shorten <jamie@jamieshorten.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/autoload/dist/ft.vim

@@ -3,7 +3,7 @@ vim9script
 # Vim functions for file type detection
 #
 # Maintainer:		The Vim Project <https://github.com/vim/vim>
-# Last Change:		2026 Mar 19
+# Last Change:		2026 Mar 20
 # Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 # These functions are moved here from runtime/filetype.vim to make startup
@@ -1888,6 +1888,8 @@ const ft_from_ext = {
   "cr": "crystal",
   # CSV Files
   "csv": "csv",
+  # Concertor
+  "cto": "concerto",
   # CUDA Compute Unified Device Architecture
   "cu": "cuda",
   "cuh": "cuda",

src/testdir/test_filetype.vim

@@ -194,6 +194,7 @@ def s:GetFilenameChecks(): dict<list<string>>
     coco: ['file.atg'],
     codeowners: ['CODEOWNERS'],
     conaryrecipe: ['file.recipe'],
+    concerto: ['file.cto'],
     conf: ['auto.master', 'file.conf', 'texdoc.cnf', '.x11vncrc', '.chktexrc', '.ripgreprc', 'ripgreprc', 'file.ctags'],
     config: ['/etc/hostname.file', 'any/etc/hostname.file', 'configure.in', 'configure.ac', 'file.at', 'aclocal.m4'],
     confini: ['pacman.conf', 'paru.conf', 'mpv.conf', 'any/.aws/config', 'any/.aws/credentials', 'any/.aws/cli/alias', 'file.nmconnection',

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    217,
 /**/
     216,
 /**/