patch 9.1.1504: filetype: numbat files are not recognized

Problem:  filetype: numbat files are not recognized
Solution: detect *.nbt files as numbat filetype (0xadk)

References:
- https://github.com/sharkdp/numbat
- https://github.com/sharkdp/numbat/tree/master/numbat/modules

closes: #17643

Signed-off-by: 0xadk <0xadk@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/filetype.vim

@@ -1771,6 +1771,9 @@ au BufNewFile,BufRead *.nt			setf ntriples
 " Nu
 au BufNewFile,BufRead *.nu		setf nu
 
+" Numbat
+au BufNewFile,BufRead *.nbt		setf numbat
+
 " Oblivion Language and Oblivion Script Extender
 au BufNewFile,BufRead *.obl,*.obse,*.oblivion,*.obscript  setf obse
 

src/testdir/test_filetype.vim

@@ -567,6 +567,7 @@ def s:GetFilenameChecks(): dict<list<string>>
     nsis: ['file.nsi', 'file.nsh'],
     ntriples: ['file.nt'],
     nu: ['file.nu'],
+    numbat: ['file.nbt'],
     obj: ['file.obj'],
     objdump: ['file.objdump', 'file.cppobjdump'],
     obse: ['file.obl', 'file.obse', 'file.oblivion', 'file.obscript'],

src/version.c

@@ -719,6 +719,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1504,
 /**/
     1503,
 /**/