systemctl: grey out tasks limit the same way we grey out the fd store limit in the output

"systemctl status systemd-logind" otherwise looks a bit weird, since the
tasks and the fdstore lines are so close to each other but formatted
quite differently when it comes to coloring.

(cherry picked from commit 54646b1ca95373dfa3ebe5d6e7e27deeed9e77b0)
(cherry picked from commit ff4b66be4a35fd21ef001bbf6492e3e1f837ee1c)
(cherry picked from commit e00cc22e30)
(cherry picked from commit e9179d051a)

src/systemctl/systemctl-show.c

@@ -692,7 +692,7 @@ static void print_status_info(
                 printf("      Tasks: %" PRIu64, i->tasks_current);
 
                 if (i->tasks_max != UINT64_MAX)
-                        printf(" (limit: %" PRIu64 ")\n", i->tasks_max);
+                        printf("%s (limit: %" PRIu64 ")%s\n", ansi_grey(), i->tasks_max, ansi_normal());
                 else
                         printf("\n");
         }