patch 9.1.1030: filetype: setting bash filetype is backwards incompatible

Problem:  filetype: setting bash filetype is backwards incompatible
Solution: revert patch v9.1.0965, detect bash scripts again as sh
          filetype

This reverts commit b9b762c21f2b61e0e7d8fee43d4d3dc8ecffd721.

related: #16309

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/autoload/dist/ft.vim b/runtime/autoload/dist/ft.vim
index 47b2fed..5bbf8ee 100644
--- a/runtime/autoload/dist/ft.vim
+++ b/runtime/autoload/dist/ft.vim
@@ -900,7 +900,6 @@
     if exists("b:is_sh")
       unlet b:is_sh
     endif
-    return SetFileTypeShell("bash", setft)
   elseif name =~ '\<sh\>' || name =~ '\<dash\>'
     # Ubuntu links "sh" to "dash", thus it is expected to work the same way
     b:is_sh = 1
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index ecdb555..6cbd102 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Jan 16
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Jan 18
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41617,8 +41617,6 @@
   |CompleteDone| autocommand in the |v:event| dictionary
 - the default fontsize for the GTK builds of Vim (Windows and Unix) has been
   increased to 12pt to accomodate modern high-dpi monitors
-- filetype detection now detects bash scripts as a separate "bash" filetype
-  instead of the "sh" filetype
 - the default value of the 'keyprotocol' option has been updated by support
   for the ghostty terminal emulator (using kitty protocol)
 - |complete_info()| returns the list of matches shown in the poppu menu via
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index a9eac86..8495e98 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -127,10 +127,6 @@
     ave: ['file.ave'],
     awk: ['file.awk', 'file.gawk'],
     b: ['file.mch', 'file.ref', 'file.imp'],
-    bash: ['.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',
-           'file.bash', 'file.bats',  'file.cygport'],
     basic: ['file.bas', 'file.bi', 'file.bm'],
     bass: ['file.bass'],
     bc: ['file.bc'],
@@ -690,13 +686,11 @@
     services: ['/etc/services', 'any/etc/services'],
     setserial: ['/etc/serial.conf', 'any/etc/serial.conf'],
     sexplib: ['file.sexp'],
-    sh: ['/usr/share/doc/bash-completion/filter.sh',
-         '/etc/udev/cdsymlinks.conf', 'any/etc/udev/cdsymlinks.conf',
-         '.ash_history', 'any/etc/neofetch/config.conf', '.xprofile',
-         'user-dirs.defaults', 'user-dirs.dirs', 'makepkg.conf', '.makepkg.conf',
-         'file.mdd', '.env', '.envrc', 'devscripts.conf', '.devscripts', 'file.lo',
-         'file.la', 'file.lai'],
-    shaderslang: ['file.slang'],
+    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', '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', 'devscripts.conf',
+         '.devscripts', 'file.lo', 'file.la', 'file.lai'],
     sieve: ['file.siv', 'file.sieve'],
     sil: ['file.sil'],
     simula: ['file.sim'],
@@ -988,11 +982,11 @@
     clojure: [['#!/path/clojure']],
     scala:  [['#!/path/scala']],
     sh:     [['#!/path/sh'],
+            ['#!/path/bash'],
+            ['#!/path/bash2'],
             ['#!/path/dash'],
             ['#!/path/ksh'],
             ['#!/path/ksh93']],
-    bash:   [['#!/path/bash'],
-            ['#!/path/bash2']],
     csh:    [['#!/path/csh']],
     tcsh:   [['#!/path/tcsh']],
     zsh:    [['#!/path/zsh']],
diff --git a/src/version.c b/src/version.c
index 6e16a5e..43a84e8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1030,
+/**/
     1029,
 /**/
     1028,