patch 8.2.4348: "legacy exe cmd" does not do what one would expect

Problem:    "legacy exe cmd" does not do what one would expect.
Solution:   Apply the "legacy" and "vim9script" command modifiers to the
            argument of ":execute".

src/ex_docmd.c

@@ -2786,6 +2786,7 @@ parse_command_modifiers(
     int	    starts_with_colon = FALSE;
 
     CLEAR_POINTER(cmod);
+    cmod->cmod_flags = sticky_cmdmod_flags;
 
     // Repeat until no more command modifiers are found.
     for (;;)