Bug #47811 ./mysql-test-run.pl --valgrind uses old (too narrow) allignment

Remove the alignment option, let valgrind use its default

mysql-test/mysql-test-run.pl

@@ -5081,7 +5081,6 @@ sub valgrind_arguments {
   else
   {
     mtr_add_arg($args, "--tool=memcheck"); # From >= 2.1.2 needs this option
-    mtr_add_arg($args, "--alignment=8");
     mtr_add_arg($args, "--leak-check=yes");
     mtr_add_arg($args, "--num-callers=16");
     mtr_add_arg($args, "--suppressions=%s/valgrind.supp", $glob_mysql_test_dir)