patch 8.2.1695: Vim9: crash when using varargs type "any"

Problem:    Vim9: crash when using varargs type "any".
Solution:   Check if uf_va_type is &t_any. (closes #6957)
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 563e281..f0c5e91 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -321,6 +321,15 @@
 
   lines =<< trim END
       vim9script
+      def Func(...l: any)
+        echo l
+      enddef
+      Func(0)
+  END
+  CheckScriptSuccess(lines)
+
+  lines =<< trim END
+      vim9script
       def Func(...l: list<string>)
         echo l
       enddef