runtime(vim): Update base-syntax, improve :set highlighting

- Match comments and trailing bar after :set without args.
- Match the <...> form for key code options.
- Remove orphaned vim_ex_python[3x]* dump files (Aliaksei Budavei).

closes: #17397

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/input/vim_ex_set.vim

@@ -1,5 +1,6 @@
 " Vim :set command
 
+
 set
 set!
 set all
@@ -37,13 +38,18 @@ set backspace-=nostop
 
 set ai nosi sw=3 tw=3
 
-set <t_#4>=^[Ot " FIXME
-set <M-b>=^[b   " FIXME
+set <t_#4>=^[Ot
+set <M-b>=^[b
 
 setlocal autoread
 setglobal noautoread
 set autoread<
 
+set " comment
+set | echo "Foo"
+set! " comment
+set! | echo "Foo"
+
 
 " :help option-backslash