patch 9.1.0596: filetype: devscripts config files are not recognized

Problem:  filetype: Debian devscripts config files are not recognized
Solution: detect devscripts.conf and .devscripts files as sh filetype
          (sourced by /bin/sh)

closes: #15227

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/filetype.vim

@@ -510,6 +510,9 @@ au BufNewFile,BufRead *.cu,*.cuh		setf cuda
 " Cue
 au BufNewFile,BufRead *.cue			setf cue
 
+" Debian devscripts
+au BufNewFile,BufRead devscripts.conf,.devscripts	setf sh
+
 " Dockerfile; Podman uses the same syntax with name Containerfile
 " Also see Dockerfile.* below.
 au BufNewFile,BufRead Containerfile,Dockerfile,dockerfile,*.[dD]ockerfile	setf dockerfile

src/testdir/test_filetype.vim

@@ -652,7 +652,8 @@ def s:GetFilenameChecks(): dict<list<string>>
     sh: ['.bashrc', '.bash_profile', '.bash-profile', '.bash_logout', '.bash-logout', '.bash_aliases', '.bash-aliases', '.bash_history', '.bash-history',
          '/tmp/bash-fc-3Ozjlw', '/tmp/bash-fc.3Ozjlw', 'PKGBUILD', 'APKBUILD', 'file.bash', '/usr/share/doc/bash-completion/filter.sh',
          '/etc/udev/cdsymlinks.conf', 'any/etc/udev/cdsymlinks.conf', 'file.bats', '.ash_history', 'any/etc/neofetch/config.conf', '.xprofile',
-         'user-dirs.defaults', 'user-dirs.dirs', 'makepkg.conf', '.makepkg.conf', 'file.mdd', 'file.cygport', '.env', '.envrc'],
+         'user-dirs.defaults', 'user-dirs.dirs', 'makepkg.conf', '.makepkg.conf', 'file.mdd', 'file.cygport', '.env', '.envrc', 'devscripts.conf',
+         '.devscripts'],
     sieve: ['file.siv', 'file.sieve'],
     sil: ['file.sil'],
     simula: ['file.sim'],

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    596,
 /**/
     595,
 /**/