patch 9.1.2062: filetype: djot files are not recognized

Problem:  filetype: djot files are not recognized
Solution: Detect *.dj and *.djot files as djot filetype
          (Hoang Nguyen).

Reference:
- https://djot.net/

closes: #19105

Signed-off-by: Hoang Nguyen <folliekazetani@protonmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/autoload/dist/ft.vim

@@ -1917,6 +1917,9 @@ const ft_from_ext = {
   # Diff files
   "diff": "diff",
   "rej": "diff",
+  # Djot
+  "dj": "djot",
+  "djot": "djot",
   # DOT
   "dot": "dot",
   "gv": "dot",

src/testdir/test_filetype.vim

@@ -242,6 +242,7 @@ def s:GetFilenameChecks(): dict<list<string>>
     dictdconf: ['dictd.conf', 'dictdfile.conf', 'dictd-file.conf'],
     diff: ['file.diff', 'file.rej'],
     dircolors: ['.dir_colors', '.dircolors', '/etc/DIR_COLORS', 'any/etc/DIR_COLORS'],
+    djot: ['file.dj', 'file.djot'],
     dnsmasq: ['/etc/dnsmasq.conf', '/etc/dnsmasq.d/file', 'any/etc/dnsmasq.conf', 'any/etc/dnsmasq.d/file'],
     dockerfile: ['Containerfile', 'Dockerfile', 'dockerfile', 'file.Dockerfile', 'file.dockerfile', 'Dockerfile.debian', 'Containerfile.something'],
     dosbatch: ['file.bat'],

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2062,
 /**/
     2061,
 /**/