runtime(misc): unset compiler in various ftplugins

just to foster best practices

closes: #15798

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

runtime/ftplugin/typst.vim

@@ -1,7 +1,7 @@
 " Vim filetype plugin file
 " Language:    Typst
 " Maintainer:  Gregory Anders
-" Last Change: 2024-07-14
+" Last Change: 2024 Oct 04
 " Based on:    https://github.com/kaarmu/typst.vim
 
 if exists('b:did_ftplugin')
@@ -9,8 +9,6 @@ if exists('b:did_ftplugin')
 endif
 let b:did_ftplugin = 1
 
-compiler typst
-
 setlocal commentstring=//\ %s
 setlocal comments=s1:/*,mb:*,ex:*/,://
 setlocal formatoptions+=croq
@@ -22,3 +20,8 @@ if get(g:, 'typst_conceal', 0)
   setlocal conceallevel=2
   let b:undo_ftplugin .= ' cole<'
 endif
+
+if !exists('current_compiler')
+  compiler typst
+  let b:undo_ftplugin ..= "| compiler make"
+endif