fix: follow-up fixes to carry gun spawns, speedloaders, ammo belts

[chaosvolt]

Checklist

Required

• I wrote the PR title in conventional commit format.
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• I linked any relevant issues using github keyword syntax so it can be closed automatically.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Purpose of change

I missed a few needed updates to carried gun groups due to lazy regex work, plus a couple other lil consistency fixes and follow-ups to Viss/Lamadus' new guns.

Describe the solution

1. Fixed some carried gun groups lacking charges-min for their magazine spawns, causing them to spawn empty.
2. Removed ammo percentage from some recently-added carry groups so they won't override the charges setting and always spawn full.
3. Set the spare belts for LMG carry groups to have 1-100 charges as with all other carry groups varying in mag loadout. Minimum of 1 instead of 0 since a belt with 0 charges shouldn't exist since they all use the ammo link system.
4. Fixed a case of wrong ammo spawning in an ammo belt.

Describe alternatives you've considered

screm

Testing

1. Checked affected files for syntax and lint errors.
2. Ported file change to playthrough build and load-tested.
3. Did itemgroup tests on thge P226 and Python, confirming both now correctly generate random amounts of ammo in their mags/speedloaders when run through itemgroup test.
4. Used my fucking eyes for once to actually confirm all relevant groups have charges-min defined for their mags.

Additional context

[chaosvolt]

This now contains a fix for a mistake I made when assigning ammo to ammobelt spawns that causes an error on triggering that spawn, in addition to the fixes for the annoying but less overt empty mag/speedloader spawns, so might be good to get this one out of the way when we can.