fix(Core/Spells): Levitate cannot be casted on mounted targets (#7258)

- Closes #7090

src/server/game/Spells/Spell.cpp

@@ -6120,6 +6120,14 @@ SpellCastResult Spell::CheckCast(bool strict)
 
                     break;
                 }
+            case SPELL_AURA_HOVER:
+                {
+                    if ((m_spellInfo->AuraInterruptFlags & AURA_INTERRUPT_FLAG_MOUNT) != 0 && m_targets.GetUnitTarget() && m_targets.GetUnitTarget()->IsMounted())
+                    {
+                        return SPELL_FAILED_NOT_ON_MOUNTED;
+                    }
+                    break;
+                }
             default:
                 break;
         }