feat(testing): add flow.collect to TestCodeGenTask

Add `flow.collect` to `TestCodeGenTask.kt` to collect the emitted values from the flow. This ensures that all values are processed and the test cases are generated correctly.

src/main/kotlin/cc/unitmesh/devti/intentions/action/task/TestCodeGenTask.kt

@@ -24,6 +24,7 @@ import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
 import kotlinx.coroutines.InternalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.runBlocking
 
 data class TestGenPromptContext(