patch 9.1.2021: filetype: fluent files are not recognized

Problem:  filetype: fluent files are not recognized
Solution: Detect *.ftl files as fluent filetype (ners)

References:
- https://projectfluent.org/

closes: #19011

Signed-off-by: ners <ners@gmx.ch>
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:		2025 Dec 22
+# Last Change:		2025 Dec 26
 # Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 # These functions are moved here from runtime/filetype.vim to make startup
@@ -1976,6 +1976,8 @@ const ft_from_ext = {
   "fish": "fish",
   # Flix
   "flix": "flix",
+  # Fluent
+  "ftl": "fluent",
   # Focus Executable
   "fex": "focexec",
   "focexec": "focexec",

src/testdir/test_filetype.vim

@@ -298,6 +298,7 @@ def s:GetFilenameChecks(): dict<list<string>>
     firrtl: ['file.fir'],
     fish: ['file.fish'],
     flix: ['file.flix'],
+    fluent: ['file.ftl'],
     focexec: ['file.fex', 'file.focexec'],
     form: ['file.frm'],
     forth: ['file.ft', 'file.fth', 'file.4th'],

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2021,
 /**/
     2020,
 /**/