patch 9.1.1787: filetype: not all Sway config files are recognized

Problem:  filetype: not all Sway config files are recognized
Solution: Detect files within */sway/config.d/* as swayconfig filetype
          (Felix Pehla).

Sways default config automatically includes files placed in
@sysconfdir@/sway/config.d/* (see config.in), so it makes sense to use
the sway syntax for those.

related: #18293

Signed-off-by: Felix Pehla <29adc1fd92@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/filetype.vim

@@ -1193,6 +1193,7 @@ au BufNewFile,BufRead */.i3/config		setf i3config
 
 " sway
 au BufNewFile,BufRead */sway/config		setf swayconfig
+au BufNewFile,BufRead */sway/config.d/*		setf swayconfig
 au BufNewFile,BufRead */.sway/config		setf swayconfig
 
 " Icon

src/testdir/test_filetype.vim

@@ -775,7 +775,8 @@ def s:GetFilenameChecks(): dict<list<string>>
     svg: ['file.svg'],
     svn: ['svn-commitfile.tmp', 'svn-commit-file.tmp', 'svn-commit.tmp'],
     sway: ['file.sw'],
-    swayconfig: ['/home/user/.sway/config', '/home/user/.config/sway/config', '/etc/sway/config', '/etc/xdg/sway/config'],
+    swayconfig: ['/home/user/.sway/config', '/home/user/.config/sway/config', '/etc/sway/config', '/etc/xdg/sway/config',
+                 '/home/user/sway/config.d/50-user.conf' ],
     swift: ['file.swift', 'file.swiftinterface'],
     swiftgyb: ['file.swift.gyb'],
     swig: ['file.swg', 'file.swig'],

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1787,
 /**/
     1786,
 /**/