Disabling VRAM power states no longer works

[KczBen]

Checklist

• The problem is not listed in the hardware support matrix as a known limitation. Examples of known driver-side issues are fans not turning on with a custom curve or inaccurate power limits on RDNA3.
• I've included a debug snapshot if the issue is related to hardware configuration

Bug description

Since version 0.5.5, disabling VRAM power states no longer works reliably. I only have state 3 (1074MHz) selected, but the memory still clocks down to state 2 (673MHz). Disabling lower power states is necessary to work around a bug in the kernel driver when using high refresh rates as seen in #350

This only occurs after clicking Apply in the GUI. On a fresh reboot, the power states get properly disabled along with applying other GPU settings.

Debug snapshot

System info

- LACT version: 0.6.0-release (commit 3fd7e0e)
- GPU model: AMD Radeon RX 6800 XT
- Kernel version: 6.12.0-x64v3-xanmod1
- Distribution: Debian Sid

[KczBen]

I tested older versions, and it appears to have broken in 0.5.5. I've edited the report to reflect that.