Upgrade to python 3.11

tox.ini

@@ -6,6 +6,7 @@ isolated_build = True
 
 [testenv]
 description = Invoke pytest to run automated tests
+basepython = python3.11
 deps =
     -r {toxinidir}/tests/requirements.txt
 setenv =
@@ -28,7 +29,7 @@ commands =
 
 [testenv:lint]
 description = Run code linters
-basepython = python3.8
+basepython = python3.11
 commands=
     black --check .
     flake8 --version
@@ -42,6 +43,7 @@ description =
     build: Build the package in isolation according to PEP517, see https://github.com/pypa/build
     clean: Remove old distribution files and temporary build artifacts (./build and ./dist)
 # https://setuptools.pypa.io/en/stable/build_meta.html#how-to-use-it
+basepython = python3.11
 skip_install = True
 changedir = {toxinidir}
 deps =
@@ -59,6 +61,7 @@ description =
     docs: Invoke sphinx-build to build the docs
     doctests: Invoke sphinx-build to run doctests
     linkcheck: Check for broken links in the documentation
+basepython = python3.11
 passenv =
     SETUPTOOLS_*
 setenv =
@@ -80,6 +83,7 @@ description =
     By default, it uses testpypi. If you really want to publish your package
     to be publicly accessible in PyPI, use the `-- --repository pypi` option.
 skip_install = True
+basepython = python3.11
 changedir = {toxinidir}
 passenv =
     # See: https://twine.readthedocs.io/en/latest/