bug(windows): `und-fonipa` is not an allowed language tag on Windows 11

Note: `und-fonipa` still doesn't work correctly in Windows, even in Win11. Trying to add it as a language tag with `Set-WinUserLanguageList` returns an error:

```
PS C:\Users\mcdurdin\desktop> $1 = Get-WinUserLanguageList
PS C:\Users\mcdurdin\desktop> $1.add("und-fonipa")
PS C:\Users\mcdurdin\desktop> Set-WinUserLanguageList $1 -Force
WARNING: If the Windows Display Language has changed, it will take effect after the next sign-in.
WARNING: If the Windows Display Language has changed, it will take effect after the next sign-in.
WARNING: If the Windows Display Language has changed, it will take effect after the next sign-in.
WARNING: The list you attempted to set contained invalid languages which were ignored
PS C:\Users\mcdurdin\desktop> Get-WinUserLanguageList

LanguageTag : en-US
Autonym : English (United States)
EnglishName : English
LocalizedName : English (United States)
ScriptName : Latin
InputMethodTips : {0409:00000409}
Spellchecking : True
Handwriting : False

LanguageTag : en-AU
Autonym : English (Australia)
EnglishName : English
LocalizedName : English (Australia)
ScriptName : Latin
InputMethodTips : {0C09:00000409}
Spellchecking : True
Handwriting : False

LanguageTag : km
Autonym : ភាសាខ្មែរ
EnglishName : Khmer
LocalizedName : Khmer
ScriptName : Khmer
InputMethodTips : {0453:{FE0420F1-38D1-4B4C-96BF-E7E20A74CFB7}{E0920C2B-4D0F-46A6-BE53-A6865B02139B}}
Spellchecking : True
Handwriting : True

LanguageTag : und-fonipa
Autonym :
EnglishName : Undetermined (und-fonipa)
LocalizedName :
ScriptName : Common
InputMethodTips : {}
Spellchecking : True
Handwriting : False

PS C:\Users\mcdurdin\desktop>
```

Documenting this here so that we can track it for future interop and reporting to Microsoft. Rediscovered this while researching:
* #10727