Update dependencies, fix config linting (#135)

Author: jens-ox

README.md

@@ -25,7 +25,7 @@ GitHub Action to set up the [pixi](https://github.com/prefix-dev/pixi) package m
 ```yml
 - uses: prefix-dev/[email protected]
   with:
-    pixi-version: v0.28.1
+    pixi-version: v0.28.2
     cache: true
     auth-host: prefix.dev
     auth-token: ${{ secrets.PREFIX_DEV_TOKEN }}