Deprecated "unload" event listener used in AccordionDetails

[SerhiiStepanenko]

Steps to reproduce

Steps:

1. Install Material-UI version @mui/material: ^6.4.2.
2. Use the AccordionDetails component in a React project.
3. Open the browser DevTools and go to the Issues tab.
4. Look for the warning: Unload event listeners are deprecated and will be removed.
5. Run a Lighthouse audit (in the Best Practices section) — the same warning is reported there.

Current behavior

• In the browser DevTools, under the Issues tab, a warning appears: Unload event listeners are deprecated and will be removed.
• Lighthouse, in the Best Practices category, also flags the use of the deprecated unload event.
• The warning originates from the AccordionDetails file within the Material-UI library.

Screenshot:
![DevTools Issues Tab]

Expected behavior

• The AccordionDetails component should not use deprecated events such as unload.
• Lighthouse and DevTools should not display any warnings.
• The Material-UI library should utilize modern methods to achieve the same functionality.

Context

• This issue prevents achieving a 100% score in the Best Practices category of Lighthouse.
• Warnings in DevTools complicate debugging and create a sense of code instability.
• Deprecated methods may be removed in the future, potentially leading to errors in the production environment.

Your environment

• Material-UI Version: 6.4.2
• React Version: 17.0.2
• Browser: Chrome 132.0.6834.160
• Operating System: Windows 11

Search keywords: AccordionDetails Unload event listener deprecated Best Practices warning Lighthouse

[mj12albert]

@SerhiiStepanenko Thanks for reporting this, would you mind providing a repro? You can fork this sandbox: https://codesandbox.io/p/sandbox/autumn-pond-v29s74

I don't see this console warning on the accordion docs page and it doesn't log that lighthouse issue when I run it

[github-actions]

Since the issue is missing key information and has been inactive for 7 days, it has been automatically closed. If you wish to see the issue reopened, please provide the missing information.