Use ClassicAPI CastSpellNoToggle for the ! anti-toggle prefix

Unify both ! mechanisms (bare !spell gate-injection and bracketed
[cond] !spell dispatch skip) on ClassicAPI's CastSpellNoToggle, which
no-ops auto-repeat (Shoot/Auto Shot/Wand) and toggle auras
(forms/stances/aspects/seals) instead of toggling them off.

- Bare !spell now just sets conditionals.noSpam (no injected gate
  conditional); removed spamConditions and GetSpammableConditional.
- Dispatch: melee Attack still uses AttackTarget (CastSpellNoToggle
  doesn't cover the melee swing). For everything else under !, keep the
  ValidatePlayerBuff anti-refresh skip (CastSpellNoToggle only covers
  true toggle auras, not regular self-buffs like Mark of the Wild),
  otherwise CastSpellNoToggle. This is more reliable for auto-repeat
  than the old CheckChanneled path.

CheckChanneled is retained (still used by the [channeled]/[checkchanneled]
conditionals).

Conditionals.lua

@@ -2140,10 +2140,6 @@ function CleveRoids.IsTargetInGroupType(target, groupType)
     return false
 end
 
-function CleveRoids.GetSpammableConditional(name)
-    return CleveRoids.spamConditions[name] or "nomybuff"
-end
-
 -- PERFORMANCE: Cache for stripped spell names (removes rank suffix)
 local _strippedNameCache = {}
 local _strippedCacheSize = 0