Mark destructors of several libraries as virtual.

src/Library/AttackLibrary.hpp

@@ -14,7 +14,7 @@ namespace CreatureLib::Library {
         AttackLibrary(size_t initialCapacity = 32)
             : _attacks(std::unordered_map<std::string, const AttackData*>(initialCapacity)){};
 
-        ~AttackLibrary() {
+        virtual ~AttackLibrary() {
             for (auto attack : _attacks) {
                 delete attack.second;
             }

src/Library/GrowthRates/GrowthRateLibrary.hpp

@@ -15,7 +15,7 @@ namespace CreatureLib::Library {
         GrowthRateLibrary(size_t initialCapacity = 10)
             : _growthRates(std::unordered_map<std::string, GrowthRate*>(initialCapacity)) {}
 
-        ~GrowthRateLibrary() {
+        virtual ~GrowthRateLibrary() {
             for (auto gr : _growthRates) {
                 delete gr.second;
             }

src/Library/ItemLibrary.hpp

@@ -13,7 +13,7 @@ namespace CreatureLib::Library {
     public:
         ItemLibrary(size_t initialCapacity = 32)
             : _items(std::unordered_map<std::string, const Item*>(initialCapacity)){};
-        ~ItemLibrary() { _items.clear(); }
+        virtual ~ItemLibrary() { _items.clear(); }
 
         [[nodiscard]] const Item* GetItem(const std::string& name) const;
         [[nodiscard]] const Item* operator[](const std::string& name) const;

src/Library/SpeciesLibrary.hpp

@@ -14,7 +14,7 @@ namespace CreatureLib::Library {
         SpeciesLibrary(size_t initialCapacity = 32)
             : _species(std::unordered_map<std::string, const CreatureSpecies*>(initialCapacity)){};
 
-        ~SpeciesLibrary() {
+        virtual ~SpeciesLibrary() {
             for (auto s : _species)
                 delete s.second;
             _species.clear();