Test to see if python 3.12 successful using GH tox (fails on local co…

…mputer; see https://pythontest.com/posts/2023/2023-10-02-py312-impimporter/)

setup.cfg

@@ -93,7 +93,7 @@ source =
  */site-packages/nmrsim/
 
 [tox:tox]
-envlist = py37, py38, py39, py310
+envlist = py37, py38, py39, py310, py311, py312
 isolated_build = True
 
 [testenv]
@@ -109,6 +109,12 @@ commands =
 # usedevelop=True should = "pip install -e ."
 usedevelop=True
 
+[testenv:py312]
+commands =
+ download = true
+ virtualenv --upgrade-embed-wheels
+ pytest {posargs}
+
 [testenv:format]
 skip_install = True
 deps =