CI: test pyfuse3 with python 3.11

.github/workflows/ci.yml

@@ -62,7 +62,7 @@ jobs:
               toxenv: py310-fuse3
             - os: ubuntu-20.04
               python-version: '3.11-dev'
-              toxenv: py311-fuse2
+              toxenv: py311-fuse3
             - os: macos-12
               python-version: '3.9'
               toxenv: py39-none  # note: no fuse testing, due to #6099, see also #6196.