GPU Texture Decoding unstable after rev 6428

[nbohr1more]

Somewhere after rev 6428 this happens:

1) Unpack dolphin
2) Start up Rogue Squadron II (default settings, Vulkan backend)
3) Game runs fine
4) Close dolphin
5) Restart dolphin
6) Start up Rogue Squadron II
7) Select Hoth stage
8) Crash (CTD) while mission loads

All subsequent attempts will crash in the same place unless you disable GPU texture decoding.