Renaming artifact names on the download page

[RedDevilus]

Basically removing mention of 64bit and duplicate AppImage naming as they don't matter much anymore.

Windows:
pcsx2-v1.7.2648-windows-64bit-AVX2.7z
into
pcsx2-v1.7.2648-windows-AVX2.7z and when SSE4 is default and does flag check, later without the CPU instruction mention
and far future
pcsx2-v1.7.2648-windows.7z

Linux:
pcsx2-v1.7.2648-linux-AppImage-64bit.AppImage
into
pcsx2-v1.7.2648-linux.AppImage

[xTVaser]

This would be done at the API level / the actual names of the files, but its also kinda difficult (but not impossible) because in some previous releases these differences do matter (where there were a 32bit and a 64bit side by side).

This means you have to have a whole bunch of conditional logic, for example, to assume 64-bit so you can still display it -- else we are then going to have another issue of people expecting it to work on their 32bit environment.

This is probably something worth looking into once the next stable is out, but ultimately the change will not happen in this repo.

[RedDevilus]

pcsx2-v1.7.2648-linux-64bit.AppImage Might be a good reduction atleast then.