Enhance icon generation and update dependencies

- Added support for generating a multi-size Windows icon (icon.ico) in the update-icons.sh script.
- Updated Cargo.toml to include the 'windows' crate with specific features for Windows support.
- Bumped version of the 'voicebox' package from 0.1.0 to 0.1.1 in Cargo.lock.
- Updated .gitignore to exclude the generated Assets.car file.

.gitignore

@@ -30,6 +30,8 @@ target/
 *.swo
 *~
 
+tauri/src-tauri/gen/Assets.car
+
 # OS
 .DS_Store
 Thumbs.db