tests: fix dropdown components test (#3504)

* ✅ (dropdownComponent.spec.ts): add missing test case for dropdownComponent to improve test coverage and ensure functionality
🔧 (dropdownComponent.spec.ts): update test case to include additional interactions with the page to simulate user behavior and improve test robustness

* ✅ (dropdownComponent.spec.ts): update mouse wheel scroll distance to 800 to improve test reliability
📝 (dropdownComponent.spec.ts): add additional wait time to ensure stability in test execution

* 🔧 (dropdownComponent.spec.ts): remove unnecessary code related to hovering and scrolling in the dropdown component test to improve test readability and maintainability

src/frontend/tests/scheduled-end-to-end/dropdownComponent.spec.ts

@@ -145,11 +145,8 @@ test("dropDownComponent", async ({ page }) => {
     expect(false).toBeTruthy();
   }
   await page.getByTestId("code-button-modal").click();
-  await page
-    .locator("#CodeEditor div")
-    .filter({ hasText: "import ChatBedrock" })
-    .nth(1)
-    .click();
+  await page.waitForTimeout(1000);
+
   await page.locator("textarea").press("Control+a");
   const emptyOptionsCode = `from langchain_community.chat_models.bedrock import BedrockChat