Smartgun Frontline Mode doesn't work with IFF Disabled

### Testmerges

#7850 #7607 #7650 #8226 #8217 #8224 #8270 #8264

### Round ID

_No response_

### Description of the bug

You can toggle IFF on the Smartgun to determine whether your bullets hit friendlies or not.
If you have IFF disabled and turn on frontline mode, you still can't hit friendlies - the Smartgun refuses to fire.
Found this out during the new Mutiny Round mechanics.

### What's the difference with what should have happened?

If IFF is disabled, you should be able to shoot at people regardless if they have IFF or not.

### How do we reproduce this bug?

1. Disable IFF on your Smartgun
2. Enable Frontline Mode on your smartgun
3. Try to shoot at someone with your IFF. Even with smartgun IFF disabled, you cannot shoot at people.
...

### Issue Bingo

- [x] Issue could be reproduced at least once
- [x] Issue happened in a recent (less than 7 days ago) round
- [x] Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)