Aspect Ratio syntax highlighting broken

[mikeybinns]

Issue Type: Bug

1. Open VS Code with extensions disabled.
2. Open a new file, and choose CSS as the language
3. Paste in the following:

.test {
  color: #fff;
  aspect-ratio: 1;
  aspect-ratio: 1 / 1;
}

What should happen:
the aspect-ratio property text should be the same colour as the color property

What actually happens:
the aspect-ratio text is a different color

Possible explaination:
The hover information for aspect-ratio says it is an experimental property, but this is not the case any more. It's now fully implemented for all modern browsers.

VS Code version: Code 1.61.2 (6cba118, 2021-10-19T14:57:20.575Z)
OS version: Windows_NT x64 10.0.22000
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz (8 x 1992)
GPU Status	2d_canvas: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: enabled_on video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.73GB (6.81GB free)
Process Argv	--crash-reporter-id 0bb0fd92-3111-45fe-9222-08f88c4f9565
Screen Reader	no
VM	0%

Extensions: none

A/B Experiments

vsliv368cf:30146710
vsreu685:30147344
python383:30185418
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pythonptprofiler:30281270
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vstes263:30335439
vscoreces:30384385
pythondataviewer:30285071
pythonvsuse255:30340121
vscod805cf:30301675
pythonvspyt200:30340761
binariesv615:30325510
vsccppwtct:30382698
bridge0708:30335490
pygetstartedt3:30385195
dockerwalkthru:30377721
bridge0723:30353136
pythonrunftest32:30373476
pythonf5test824:30373475
javagetstartedt:30391933
pythonvspyt187:30373474
vsqsis300:30386381
vsaa593:30376534
vssld246:30386377

[alexr00]

Thanks for clear repro steps! I've moved this issue to the repository that we pull our css syntax highlighting grammar from: atom/language-css#190