fix: dispose CancellationTokenSource in tests

Author: dluc

tests/Core.Tests/Embeddings/Cache/SqliteEmbeddingCacheTests.cs

@@ -314,7 +314,7 @@ public async Task StoreAsync_WithCancellationToken_ShouldRespectCancellation()
         using var cache = new SqliteEmbeddingCache(this._tempDbPath, CacheModes.ReadWrite, this._loggerMock.Object);
         var key = EmbeddingCacheKey.Create("OpenAI", "model", 1536, true, "test text");
         var vector = new float[] { 0.1f, 0.2f, 0.3f };
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert
@@ -328,7 +328,7 @@ public async Task TryGetAsync_WithCancellationToken_ShouldRespectCancellation()
         // Arrange
         using var cache = new SqliteEmbeddingCache(this._tempDbPath, CacheModes.ReadWrite, this._loggerMock.Object);
         var key = EmbeddingCacheKey.Create("OpenAI", "model", 1536, true, "test text");
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert

tests/Core.Tests/Embeddings/CachedEmbeddingGeneratorTests.cs

@@ -459,7 +459,7 @@ public async Task GenerateAsync_WithCancellation_ShouldPropagate()
             this._cacheMock.Object,
             this._loggerMock.Object);
 
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert

tests/Core.Tests/Embeddings/Providers/AzureOpenAIEmbeddingGeneratorTests.cs

@@ -228,7 +228,7 @@ public async Task GenerateAsync_WithCancellation_ShouldPropagate()
         var generator = new AzureOpenAIEmbeddingGenerator(
             httpClient, "https://myservice.openai.azure.com", "deployment", "model", "key", 1536, true, this._loggerMock.Object);
 
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert - TaskCanceledException inherits from OperationCanceledException

tests/Core.Tests/Embeddings/Providers/HuggingFaceEmbeddingGeneratorTests.cs

@@ -283,7 +283,7 @@ public async Task GenerateAsync_WithCancellation_ShouldPropagate()
         var generator = new HuggingFaceEmbeddingGenerator(
             httpClient, "hf_token", "model", 384, true, null, this._loggerMock.Object);
 
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert - TaskCanceledException inherits from OperationCanceledException

tests/Core.Tests/Embeddings/Providers/OllamaEmbeddingGeneratorTests.cs

@@ -220,7 +220,7 @@ public async Task GenerateAsync_WithCancellation_ShouldPropagate()
         var generator = new OllamaEmbeddingGenerator(
             httpClient, "http://localhost:11434", "qwen3-embedding", 1024, true, this._loggerMock.Object);
 
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert - TaskCanceledException inherits from OperationCanceledException

tests/Core.Tests/Embeddings/Providers/OpenAIEmbeddingGeneratorTests.cs

@@ -249,7 +249,7 @@ public async Task GenerateAsync_WithCancellation_ShouldPropagate()
         var generator = new OpenAIEmbeddingGenerator(
             httpClient, "test-key", "model", 1536, true, null, this._loggerMock.Object);
 
-        var cts = new CancellationTokenSource();
+        using var cts = new CancellationTokenSource();
         cts.Cancel();
 
         // Act & Assert - TaskCanceledException inherits from OperationCanceledException