Fixed wrong support folder when using .NET 8 on Unix

[Mailaender]

It saves into ~/Documents/.config/openra/ instead of ~/.config/openra/ on Linux. https://learn.microsoft.com/dotnet/core/compatibility/core-libraries/8.0/getfolderpath-unix Discovered during #21577. Also effects https://launchpad.net/~xtradeb/+archive/ubuntu/play/+build/28130160 which is already on .NET 8.

[RoosterDragon]

So to make sure I'm reading the notes correctly:

• Personal resolves to $HOME in net6, but will resolve to $HOME/Documents (or other things) in net8
• UserProfile resolves to $HOME in both net6 and net8

Therefore making this changes doesn't break net6, and fixes us in prep for net8.

1. Is the above correct?
2. Should adjust the macOS case as well?
3. And the default case?
4. And the Windows case just to match - or does that need to stay as is to prevent any paths changing?

[anvilvapre]

ms will always stay ms.

[pchote]

According to https://learn.microsoft.com/en-gb/dotnet/core/compatibility/core-libraries/8.0/getfolderpath-unix#macos, yes, macOS will also need to be changed.

[PunkPun]

Confirmed that updating it for macOS fixes my issues with #21577, and doesn't mess up current bleed build

[PunkPun]

changelog

[RoosterDragon]

The default case also appears to be a Linux flavour as well, I think that should've been updated too.

[Mailaender]

No, that would be covered by the platform Linux case. Did I miss BSD?

[RoosterDragon]

I don't know what platforms would trigger the default case, but it's clearly largely a copy-paste of the Linux case so it makes to keep them aligned rather than not.