Update Decky-Undervolt to 1.0.9

[totallynotbakadestroyer]

Decky-Undervolt

Unlocked undervolting up to 100, added a FAQ.

Task Checklist

Developer

• I am the original author or an authorized maintainer of this plugin.
• I have abided by the licenses of the libraries I am utilizing, including attaching license notices where appropriate.

Plugin

• I have verified that my plugin works properly on the Stable and Beta update channels of SteamOS.
• I have verified my plugin is unique or provides more/alternative functionality to a plugin already on the store.

Backend

• No: I am using a custom backend other than Python.
• Yes: I am using a tool or software from a 3rd party FOSS project that does not have it's dependencies statically linked.
• No: I am using a custom binary that has all of it's dependencies statically linked.

Community

• I have tested and left feedback on two other pull requests for new or updating plugins.
• I have commented links to my testing report in this PR.

Testing

• Tested by a third party on SteamOS Stable or Beta update channel.

[EMERALD0874]

@totallynotbakadestroyer Please read the comment under the Testing section and delete the checkbox that doesn't match the necessary testing for your plugin. When done, please mention me in a reply so the Decky team can review the update.

[totallynotbakadestroyer]

@EMERALD0874 fixed

[TrainDoctor]

Code changes look good for testing.