Update steam-librarian to v1.0.6

[luthor112]

Steam Librarian

• Remove dead code
• New feature: Mark shortcuts as not installed
• New feature: Add Restart menu item
• Update libraries, bump version, update ReadMe, fix loading

Task Checklist

Developer

• I am the original author or an authorized maintainer of this plugin.
• I have complied with all license requirements for the libraries used, including providing appropriate notices where necessary.
• My plugin is fully open source and does not depend on any external paid services, except for widely trusted and well-known platforms. Additionally, neither I nor anyone associated with me profits from any such services.

Plugin Functionality

• I have tested the plugin on both the Stable and Beta SteamOS update channels.

Backend Configuration

• Yes: I use a standard Millennium python backend in my plugin.
• No: I use custom binaries that or rely on other FOSS projects that aren't written directly using Millennium's python backend.

Community Contribution

• I have tested and left feedback on two other plugin pull requests.
• I have added links to those feedback comments in this PR.

---

Testing Instructions

• Verified by a third party on Steam Client Stable.
• Verified by a third party on Steam Client Beta.

[shdwmtr]

Has this been tested on Steam beta and stable?

[luthor112]

I only test on stable, since (AFAIK) Millennium is not supported on Steam Beta.
Has that changed?