Update Python.gitignore (pixi)

That's what pixi itself adds to .gitignore when using "pixi init".

Python.gitignore

@@ -123,6 +123,7 @@ ipython_config.py
 #   Pixi creates a virtual environment in the .pixi directory, just like venv module creates one
 #   in the .venv directory. It is recommended not to include this directory in version control.
 .pixi
+!.pixi/config.toml
 
 # PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
 __pypackages__/