Testing iframes with Playwright/axe-core

### Product

axe-core

### Product Version

_No response_

### Latest Version

- [X] I have tested the issue with the latest version of the product

### Issue Description

#### Expectation
I am working on accessibility testing with Playwright and @axe-core, following the instructions [here](https://playwright.dev/docs/accessibility-testing). My page contains iframes and I would like to scan and analyze the content inside them.

#### Actual
When scanning the page object as per the instructions, the `incomplete` property of the `accessibilityScanResults` object contains this:

```
{
id: 'frame-tested',
impact: 'critical',
tags: [Array],
description: 'Ensures and <frame> elements contain the axe-core script',
help: 'Frames should be tested with axe-core',
helpUrl: 'https://dequeuniversity.com/rules/axe/4.9/frame-tested?application=playwright',
nodes: [Array]
}
```
The link provided under the helpUrl property says to "Ensure iframe and frame elements contain the axe-core script" but doesn't provide an example of how to achieve that.

#### How to Reproduce
When testing a page containing an iframe with code provided in the documentation:

`const accessibilityScanResults = await new AxeBuilder({ page }).analyze()`

the above issue occurs. it does not occur on pages without iframes. It happens even when trying to explicitly include the iframe as per the documentation:

`const accessibilityScanResults = await new AxeBuilder({ page }).include('#sbox-iframe').analyze()`

#### Additional context
Any thing else we should know about the issue?