Launchers don't have appropriate check for ammo count

## Testmerges
#12627: 'Tyrargo Rift (2) - Various Alterations' by Steelpoint at commit 73b8f408b2
#12640: 'Fuel pumps have health during hijack + bullet ping fix + trapper shotgun flag fix' by Drulikar at commit 804940f534
#12721: 'Assorted Sound Fixes' by fira at commit 85e10735bf
#12823: 'Clamp lower end of scuffle damage and reduce variability' by Drulikar at commit 7a93a4328c
#12824: 'Bundles Wound Overlay Updates' by fira at commit 6b48f2d5f1
#12825: 'Optimize /datum/controller/subsystem/minimaps/proc/add_marker' by fira at commit 1a869a8443
#11085: 'Surgery QOL update (better descriptions, better sprites, more pain and screaming, add sounds to procedures that did not have any)' by Puckaboo2 at commit 812ce9b06e
#12753: 'PR Stack - Movement Optimizations' by fira at commit 3082e3cb2b
#12322: 'Fort McNeil - (Lowpop) Ground Map' by Steelpoint at commit d16cb3bb7b
#12865: 'Fix: Ammo Counter not working on burst-fire. + Akimbo signal override + Misc' by MistChristmas at commit 0c7d1b0edf
#12840: 'Marines with leadership can now point and outline other mobs' by Bibby0110 at commit 36dc369653

## Round ID
35739

## Description of the bug
When the M5 RPG is examined, it will always say that it is empty, even when a rocket is present.

## What's the difference with what should have happened?
When loaded, check reports it is loaded with x

## How do we reproduce this bug?
Examine M5 RPG in any case.

## Attached logs
```
N/A
```

## Additional details
- Author: sallyrred
- Admin: KiVts
- Note: None

Search the codebase for the M5 RPG definition and its examine behavior, then reproduce the issue with an unloaded and loaded launcher. Done means examining the M5 RPG reports that it is empty when unloaded and reports the loaded rocket count when a rocket is present.

Written by the indexing model from the issue text.