perf: Dispose HashtableEx to return memory to the pool

src/Uno.UI/UI/Xaml/DependencyObjectStore.AncestorsDictionary.cs

@@ -49,6 +49,9 @@ internal void Set(object key, bool isAncestor)
 
 			internal void Clear()
 				=> _entries.Clear();
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/DependencyObjectStore.Binder.cs

@@ -257,6 +257,7 @@ private void BinderDispose()
 			}
 
 			_properties.Dispose();
+			_childrenBindableMap.Dispose();
 		}
 
 		private void OnDataContextChanged(object? providedDataContext, object? actualDataContext, DependencyPropertyValuePrecedences precedence)

src/Uno.UI/UI/Xaml/DependencyObjectStore.cs

@@ -1546,6 +1546,10 @@ void Propagate(DependencyObjectStore store)
 					}
 				}
 			}
+
+			// Explicit dispose to return HashtableEx's internal array to the pool
+			// without having to rely on GC's finalizers.
+			ancestors.Dispose();
 		}
 
 		private static bool IsAncestor(DependencyObject? instance, AncestorsDictionary map, object ancestor)

src/Uno.UI/UI/Xaml/DependencyProperty.Dictionary.FrameworkPropertiesForType.cs

@@ -39,6 +39,9 @@ internal void Add(_Key key, DependencyProperty[] value)
 				=> _entries.Add(key, value);
 
 			internal void Clear() => _entries.Clear();
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/DependencyProperty.Dictionary.NameToProperty.cs

@@ -50,6 +50,9 @@ internal void Remove(PropertyCacheEntry propertyCacheEntry)
 			internal int Count => _entries.Count;
 
 			internal void Clear() => _entries.Clear();
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/DependencyProperty.Dictionary.PropertiesRegistry.cs

@@ -71,6 +71,9 @@ private bool TryGetTypeTable(Type type, out HashtableEx? table)
 				table = null;
 				return false;
 			}
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/DependencyProperty.Dictionary.TypeNullableDictionary.cs

@@ -42,6 +42,9 @@ internal void Add(Type key, bool isNullable)
 
 			internal void Clear()
 				=> _entries.Clear();
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/DependencyProperty.Dictionary.TypeToProperties.cs

@@ -30,6 +30,9 @@ internal void Add(Type key, DependencyProperty[] dependencyProperty)
 
 			internal void Clear()
 				=> _entries.Clear();
+
+			internal void Dispose()
+				=> _entries.Dispose();
 		}
 	}
 }

src/Uno.UI/UI/Xaml/PropertyMetadataDictionary.cs

@@ -59,5 +59,8 @@ internal PropertyMetadata FindOrCreate(Type ownerType, CreationHandler createHan
 
 			return metadata;
 		}
+
+		internal void Dispose()
+			=> _table.Dispose();
 	}
 }