alternative fix: item spawning spells with no min/max damage

[mqrause]

Summary

None

Purpose of change

Alternative to #64965, recreates the old behavior so it doesn't break existing json.

Describe the solution

Always spawn at least one item/item group, even with no damage defined.

Describe alternatives you've considered

Testing

Additional context

@casswedson probably of interest to you. I can't judge what the actually preferable solution would be since I don't know too much about spells.

[casswedson]

I created a new character and gave myself a level 4 repelling arc; it's not doing the thing

• OS: Linux
  • OS Version: Distributor ID: Pop; Description: Pop!_OS 22.04 LTS; Release: 22.04; Codename: jammy;
• Game Version: afda5f6 [64-bit]
• Graphics Version: Tiles
• Game Language: System language []
• Mods loaded: [
  Dark Days Ahead [dda],
  Disable NPC Needs [no_npc_food],
  Bionic Professions [package_bionic_professions],
  Magiclysm [magiclysm]
  ]

[mqrause]

I'm pretty sure that's just a UI bug. And I'm also actually fairly sure it's been like that before? Or it wasn't actually my fault and someone changed spell damage calculations.

[casswedson]

the only thing I can say is that the spell does not work, if I cast it does not spawn anything

[mqrause]

Oh god, yeah, I see my stupid mistake. Using std::min instead of std::max. Sorry about that.