Settings.json incorrectly marks permitted extension versions as not accepted

### Description

In 1.129.1, it was possible to allow specific versions or platforms when specifying a list of approved extensions, as documented here: https://code.visualstudio.com/docs/enterprise/extensions#_allow-specific-versions-or-platforms
In 1.130.0 this feature no longer displays properly, instead showing the warning:
"Incorrect type. Expected one of boolean, string.
Value is not accepted. Valid values: true, false, "stable".(1)"

This is the warning given when the following settings snippet is placed in my settings.json file; where the `"1.31.3"` is marked with a yellow underline.
```
"extensions.allowed": {
"GitHub.copilot-chat" : "stable",
"ms-vscode.cpptools" : ["1.31.4"],
...
}
```

In spite of this warning, the extensions with versions specified still work as normal, so I suspect this is a format/display issue more than the core functionality not supporting this anymore.

### Issue Details

Item|Value
---|---
Issue Category|Bug
Target|Visual Studio Code
VS Code Version|Code 1.130.0 (1b6a188127eeaf9194f945eb6eb89a657e93c54c, 2026-07-22T14:55:04Z)
OS Version|Windows_NT x64 10.0.26200

System Info

Item|Value
---|---
VS Code Version|Code 1.130.0 (1b6a188127eeaf9194f945eb6eb89a657e93c54c, 2026-07-22T14:55:04Z)
OS Version|Windows_NT x64 10.0.26200
CPUs|Intel(R) Core(TM) Ultra 7 155U (14 x 2688)
GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x8086, DEVICE=0x7d45 [Intel(R) Graphics], DRIVER_VENDOR=Intel, DRIVER_VERSION=32.0.101.8860 *ACTIVE*
GPU1: VENDOR= 0x8086, DEVICE=0x7d45 [Intel(R) Graphics], DRIVER_VERSION=32.0.101.8860
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8875
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off
Load (avg)|
Memory (System)|31.47GB (8.36GB free)
Process Argv|--crash-reporter-id 49b52df3-3859-40d5-ae2a-b634022346e7
Screen Reader|no
User Agent|Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Code/1.130.0 Chrome/148.0.7778.280 Electron/42.6.0 Safari/537.36
Installation pure|true