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>
diff --git a/runtime/ftplugin/context.vim b/runtime/ftplugin/context.vim
index 0070f85..b39a306 100644
--- a/runtime/ftplugin/context.vim
+++ b/runtime/ftplugin/context.vim
@@ -4,7 +4,7 @@
 # Language:           ConTeXt typesetting engine
 # Maintainer:         Nicola Vitacolonna <nvitacolonna@gmail.com>
 # Former Maintainers: Nikolai Weibull <now@bitwi.se>
-# Latest Revision:    2023 Dec 26
+# Latest Revision:    2024 Oct 04
 
 if exists("b:did_ftplugin")
   finish
@@ -14,10 +14,6 @@
 
 b:did_ftplugin = 1
 
-if !exists('current_compiler')
-  compiler context
-endif
-
 b:undo_ftplugin = "setl com< cms< def< inc< sua< fo< ofu<"
 
 setlocal comments=b:%D,b:%C,b:%M,:%
@@ -106,6 +102,12 @@
   endfor
 endif
 
+if !exists('current_compiler')
+  b:undo_ftplugin ..= "| compiler make"
+  compiler context
+endif
+
+b:undo_ftplugin ..= "| sil! delc -buffer ConTeXt | sil! delc -buffer ConTeXtLog | sil! delc -buffer ConTeXtJobStatus | sil! delc -buffer ConTeXtStopJobs"
 # Commands for asynchronous typesetting
 command! -buffer -nargs=? -complete=buffer ConTeXt          context.Typeset(<q-args>)
 command! -buffer -nargs=0                  ConTeXtLog       context.Log('%')