[Bug]: Overlays end up at (0,0) in older CEF hosts due to using CSS Transforms Level 2 'translate' property in PlacementController's computePlacement()

### Code of conduct

- [x] I agree to follow this project's code of conduct.

### Impacted component(s)

Action Menu, Combobox, Menu, Overlay, Picker, Other

### Expected behavior

The overlay/dialog should appear at the computed `x`/`y` offsets relative to its trigger by applying the position from `computePosition()`.

In hosts with older CEF with no CSS Transforms Level 2 `translate `support - for example Adobe CEP 11 panels running CEF 3 branch 3729 (Chromium 88) - the code should fallback to the long-standing `transform: translate(...)` API so overlays still render in the correct spot.

### Actual behavior

Because [the code does:](https://github.com/adobe/spectrum-web-components/blob/cc6e91eca2b5d84769d2ed42758299e2ec57e3b2/packages/overlay/src/PlacementController.ts#L356)

```
// Update the overlay's style with the computed position.
Object.assign(target.style, {
top: '0px',
left: '0px',
translate: `${roundByDPR(x)}px ${roundByDPR(y)}px`,
});
```

it relies on the CSS Transforms Level 2 `translate `property, which is not implemented in CEF 3 branch 3729 (Chromium 88). In that environment, setting `translate` is a no-op, so the overlay falls back to its default origin (0,0).

### Screenshots



### What browsers are you seeing the problem in?

Chrome

### How can we reproduce this issue?

1. Go to '...'
2. Click on '....'
3. Scroll to '....'
4. Check console
5. See error

### Sample code or abstract reproduction which illustrates the problem

Use one of the examples from [Spectrum Web Components documentation](https://opensource.adobe.com/spectrum-web-components/index.html) in Adobe CEP 11 extension - for example, for [sp-picker](https://opensource.adobe.com/spectrum-web-components/components/picker/#labels)

OR

In a Spectrum Web Components project, import and register Overlay:

```
import '@spectrum-web-components/overlay/sp-overlay.js';

import '@spectrum-web-components/picker/sync/sp-picker.js';
import '@spectrum-web-components/menu/sp-menu.js';
import '@spectrum-web-components/menu/sp-menu-item.js';
import '@spectrum-web-components/menu/sp-menu-divider.js';
// …
```
Add this HTML in a CEP panel:

```

Deselect
Select inverse
Feather...
Select and mask...

Save selection
Make work path

```

Package and load as an Adobe CEP 11 extension.

Click at picker and observe the dialog rendered at (0,0).

### Severity

SEV 4

### Logs taken while reproducing problem

_No response_

### Would you like to track this issue in Jira?

- [x] Yes, please tell me the ticket number!

Start in packages/overlay/src/PlacementController.ts at computePlacement(), especially the style update around line 356. Check how the computed x/y offsets are applied and verify the placement behavior in an Adobe CEP 11 panel using CEF 3 branch 3729. Done means the overlay appears at the computed position in older hosts as well as modern browsers.

Written by the indexing model from the issue text.