CGunWeapon: Make destructor virtual

This class is used as polymorphic type, so the destructor should be
marked as virtual to prevent any potential undefined behavior.

This also more closely matches the GM8E v0 binary itself.

Runtime/Weapon/CGunWeapon.cpp

@@ -75,6 +75,8 @@ CGunWeapon::CGunWeapon(CAssetId ancsId, EWeaponType type, TUniqueId playerId, EM
   BuildDependencyList(x200_beamId);
 }
 
+CGunWeapon::~CGunWeapon() = default;
+
 void CGunWeapon::AllocResPools(CPlayerState::EBeamId beam) {
   const auto& wPair = g_tweakGunRes->GetWeaponPair(beam);
   const char* const* muzzleNames = &skMuzzleNames[size_t(beam) * 2];