patch 9.0.1409: racket files are recognized as scheme

Problem:    Racket files are recognized as scheme.
Solution:   Recognize rackets files separately. (Gabriel Kakizaki,
            closes #12164, closes #12162)

Author: kakig

runtime/filetype.vim

@@ -1655,6 +1655,9 @@ au BufRead,BufNewFile qmldir			setf qmldir
 " Quarto
 au BufRead,BufNewFile *.qmd			setf quarto
 
+" Racket (formerly detected as "scheme")
+au BufNewFile,BufRead *.rkt,*.rktd,*.rktl	setf racket
+
 " Radiance
 au BufNewFile,BufRead *.rad,*.mat		setf radiance
 
@@ -1922,8 +1925,8 @@ au BufNewFile,BufRead .zprofile,*/etc/zprofile,.zfbfmarks  setf zsh
 au BufNewFile,BufRead .zshrc,.zshenv,.zlogin,.zlogout,.zcompdump setf zsh
 au BufNewFile,BufRead *.zsh			setf zsh
 
-" Scheme
-au BufNewFile,BufRead *.scm,*.ss,*.sld,*.rkt,*.rktd,*.rktl	setf scheme
+" Scheme ("racket" patterns are now separate, see above)
+au BufNewFile,BufRead *.scm,*.ss,*.sld		setf scheme
 
 " Screen RC
 au BufNewFile,BufRead .screenrc,screenrc	setf screen

src/testdir/test_filetype.vim

@@ -475,6 +475,7 @@ let s:filename_checks = {
     \ 'quake': ['anybaseq2/file.cfg', 'anyid1/file.cfg', 'quake3/file.cfg', 'baseq2/file.cfg', 'id1/file.cfg', 'quake1/file.cfg', 'some-baseq2/file.cfg', 'some-id1/file.cfg', 'some-quake1/file.cfg'],
     \ 'quarto': ['file.qmd'],
     \ 'r': ['file.r', '.Rprofile', 'Rprofile', 'Rprofile.site'],
+    \ 'racket': ['file.rkt', 'file.rktd', 'file.rktl'],
     \ 'radiance': ['file.rad', 'file.mat'],
     \ 'raku': ['file.pm6', 'file.p6', 'file.t6', 'file.pod6', 'file.raku', 'file.rakumod', 'file.rakudoc', 'file.rakutest'],
     \ 'raml': ['file.raml'],
@@ -513,7 +514,7 @@ let s:filename_checks = {
     \ 'sather': ['file.sa'],
     \ 'sbt': ['file.sbt'],
     \ 'scala': ['file.scala'],
-    \ 'scheme': ['file.scm', 'file.ss', 'file.sld', 'file.rkt', 'file.rktd', 'file.rktl'],
+    \ 'scheme': ['file.scm', 'file.ss', 'file.sld'],
     \ 'scilab': ['file.sci', 'file.sce'],
     \ 'screen': ['.screenrc', 'screenrc'],
     \ 'scss': ['file.scss'],

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1409,
 /**/
     1408,
 /**/