Fix VariantAnalysisActions tests

Author: tuan-nguen

extensions/ql-vscode/src/view/variant-analysis/__tests__/VariantAnalysisActions.spec.tsx

@@ -50,7 +50,7 @@ describe(VariantAnalysisActions.name, () => {
       variantAnalysisStatus: VariantAnalysisStatus.Canceling,
     });
 
-    const button = screen.getByText("Stopping query");
+    const button = await screen.findByText("Stopping query");
     expect(button).toBeInTheDocument();
     expect(button).toBeDisabled();
   });