remove some duplicate dict lookups (#19138)

src/Avalonia.Base/Collections/AvaloniaDictionary.cs

@@ -167,9 +167,8 @@ namespace Avalonia.Collections
         /// <inheritdoc/>
         public bool Remove(TKey key)
         {
-            if (_inner.TryGetValue(key, out var value))
+            if (_inner.Remove(key, out var value))
             {
-                _inner.Remove(key);
                 PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
                 PropertyChanged?.Invoke(this, new PropertyChangedEventArgs($"{CommonPropertyNames.IndexerName}[{key}]"));
 

src/Avalonia.Base/Controls/NameScope.cs

@@ -68,9 +68,8 @@ namespace Avalonia.Controls
             else
             {
                 _inner.Add(name, element);
-                if (_pendingSearches.TryGetValue(name, out var tcs))
+                if (_pendingSearches.Remove(name, out var tcs))
                 {
-                    _pendingSearches.Remove(name);
                     tcs.SetResult(element);
                 }
             }

src/Avalonia.Base/Media/MediaContext.cs

@@ -173,9 +173,8 @@ internal partial class MediaContext : ICompositorScheduler
 
     public void RemoveTopLevel(object key)
     {
-        if (_topLevels.TryGetValue(key, out var info))
+        if (_topLevels.Remove(key, out var info))
         {
-            _topLevels.Remove(key);
             info.Renderer.Stop();
         }
     }

src/Avalonia.Base/Utilities/SmallDictionary.cs

@@ -292,9 +292,8 @@ internal struct InlineDictionary<TKey, TValue> : IEnumerable<KeyValuePair<TKey,
         }
         else if (_data is Dictionary<TKey, TValue?> dic)
         {
-            if (!dic.TryGetValue(key, out value))
+            if (!dic.Remove(key, out value))
                 return false;
-            dic.Remove(key);
         }
 
         value = default;