runtime(vim): Update base-syntax, fix Vim9 :import expression comment handling

The required space in Vim9 continuation comments (#\ comment) was
accidentally removed in commit 6acca4b as trailing whitespace.

closes: #17573

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index 10cefd3..71d7f37 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -2,7 +2,7 @@
 " Language:	   Vim script
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
-" Last Change:	   2025 Jun 18
+" Last Change:	   2025 Jun 20
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -391,7 +391,7 @@
             \\|
           \\%(^\s*#.*\)\@<=$
             \\|
-          \\n\s*\\\|\n\s*#\\
+          \\n\s*\%(\\\|#\\ \)
         \+
         \ matchgroup=vimCommand
         \ end="\s\+\zsas\ze\s\+\h"
@@ -403,7 +403,7 @@
 else
   syn region	vimImportFilename contained
         \ start="\S"
-        \ skip=+\n\s*\\\|\n\s*"\\ +
+        \ skip=+\n\s*\%(\\\|"\\ \)+
         \ matchgroup=vimCommand
         \ end="\s\+\zsas\ze\s\+\h"
         \ matchgroup=NONE