Removed pixi generated files and (probably) erroneous additions to .gitignore

Author: georgweiss

.gitattributes

@@ -132,6 +132,3 @@ docs/source/_ext/**/*.pyc
 # Ignore pip installation metadata
 docs/phoebus_docs.egg-info/
 *.pyc
-# pixi environments
-.pixi/*
-!.pixi/config.toml